Patent Publication Number: US-2021168338-A1

Title: Light emitting apparatus and projector

Description:
The present application is based on, and claims priority from JP Application Serial Number 2019-216437, filed Nov. 29, 2019, and Serial Number 2020-158302, filed Sep. 23, 2020, the disclosures of which are hereby incorporated by reference herein in their entireties. 
     BACKGROUND 
     1. Technical Field 
     The present disclosure relates to a light emitting apparatus and a projector. 
     2. Related Art 
     There has been a known light emitting apparatus using a photonic crystal. For example, JP-A-2009-43918 discloses a surface emitting laser having a structure which includes a two-dimensional photonic crystal and a one-dimensional photonic crystal and in which a photonic band edge of the one-dimensional photonic crystal reflects light propagating in the in-plane directions of the two-dimensional photonic crystal. 
     A study on configuration of a compact projector using a surface light source, such as that described above has been conducted. In this case, a light modulating apparatus can be efficiently illuminated if the surface light source can be disposed in a position nearest to the light modulating apparatus. However, to provide a space for cooling the light modulating apparatus or a space for disposing a variety of optical elements, for example, a lens, the surface light source and the light modulating apparatus need to be so disposed as to be separate from each other by a predetermined distance. For example, when the light modulating apparatus is formed of a liquid crystal display device, a space for disposing a polarizer is required between the surface light source and the liquid crystal display device. 
     When the light flux emitted from the surface light source is not a parallelized light flux but is a divergent light flux, the diameter and outer shape of the light flux change as the distance from the surface light source increases. Therefore, when the light modulating apparatus is disposed in a position remote from the surface light source, the outer shape of the light flux incident on the light modulating apparatus differs from the outer shape of the light flux immediately after the light flux is emitted from the surface light source. An image formation region of the light modulating apparatus has a rectangular shape in many cases. Even when the surface light source is configured to have a rectangular light emission region in accordance with the rectangular image formation region, the outer shape of the light flux is so deformed as to approach a circular shape as the distance from the surface light source increases. As a result, the outer shape of the light flux does not match with the shape of the image formation region of the light modulating apparatus, resulting in a problem of insufficient illumination of the image formation region. 
     SUMMARY 
     To solve the problem described above, a light emitting apparatus according to an aspect of the present disclosure includes a base and a plurality of resonators provided at a first surface of the base. The plurality of resonators each include a photonic crystal structure having a periodic structure. The plurality of resonators form a light emission region that emits light that the periodic structure allows to resonate, and the plurality of resonators include a first resonator and a second resonator. A distance from a center of the light emission region to the second resonator is longer than a distance from the center of the light emission region to the first resonator. A resonance length of the second resonator is longer than the resonance length of the first resonator. 
     In the light emitting apparatus according to the aspect of the present disclosure, the light emission region may have a plurality of divided regions concentric around the center. The plurality of divided regions may include a first divided region and a second divided region. A plurality of the first resonators may be provided in the first divided region, and a plurality of the second resonators may be provided in the second divided region. The plurality of first resonators in the first divided region may have the same resonance length, and the plurality of second resonators in the second divided region may have the same resonance length. 
     In the light emitting apparatus according to the aspect of the present disclosure, an intensity distribution of a light flux emitted from the light emission region may be so shaped that the intensity at a peripheral portion of the light emission region is higher than the intensity at a central portion of the light emission region. 
     In the light emitting apparatus according to the aspect of the present disclosure, the plurality of resonators may be provided on a first surface of the base via at least one intermediate base. 
     In the light emitting apparatus according to the aspect of the present disclosure, the at least one intermediate base may include a first intermediate base and a second intermediate base, the first resonator may be provided on the first intermediate base, and the second resonator may be provided on the second intermediate base. 
     In the light emitting apparatus according to the aspect of the present disclosure, the plurality of resonators may include a plurality of the first resonators and a plurality of the second resonators, the plurality of first resonators may be provided on the first intermediate base, and the plurality of second resonators are provided on the second intermediate base. 
     A projector according to another aspect of the present disclosure includes the light emitting apparatus according to the aspect of the present disclosure, a light modulating apparatus that modulates light emitted from the light emitting apparatus in accordance with image information to produce image light, and a projection optical apparatus that projects the image light emitted from the light modulating apparatus. 
     In the projector according to the aspect of the present disclosure, a planar shape of the light emission region may be similar to a planar shape of an image formation region of the light modulating apparatus. 
     The projector according to the aspect of the present disclosure may further include a relay system provided between the light emitting apparatus and the light modulating apparatus. 
     The projector according to the aspect of the present disclosure may further include a light guide provided between the light emitting apparatus and the light modulating apparatus. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a schematic configuration diagram of a projector according to a first embodiment. 
         FIG. 2  is a plan view of a light emitter in the first embodiment. 
         FIG. 3  is a plan view of a resonator. 
         FIG. 4  is a cross-sectional view of the resonator taken along the line IV-IV in  FIG. 3 . 
         FIG. 5  shows the light orientation angle of light emitted from the resonator. 
         FIG. 6  shows the light orientation angles of the light emitted from a plurality of resonators located in different positions in a light emission region. 
         FIG. 7  shows the positions where the light emitted from the plurality of resonators reach an image formation region of a light modulating apparatus. 
         FIG. 8  shows the planar shape and the intensity distribution of a light flux. 
         FIG. 9  shows the planar shape and the intensity distribution of a light flux from a light emitting apparatus according to Comparative Example. 
         FIG. 10  is a plan view of a light emitting apparatus according to a second embodiment. 
         FIG. 11  shows the relationship between the distance from the center of the light emission region and the size of the resonators. 
         FIG. 12  is a cross-sectional view of a light emitting apparatus according to a third embodiment. 
         FIG. 13  is a cross-sectional view of a light emitting apparatus according to a fourth embodiment. 
         FIG. 14  is a cross-sectional view of a light emitting apparatus according to a variation. 
         FIG. 15  is a cross-sectional view of a light emitting apparatus showing a first configuration example of an electrode. 
         FIG. 16  is a cross-sectional view of a light emitting apparatus showing a second configuration example of the electrode. 
         FIG. 17  is a schematic configuration diagram of a projector according to a fifth embodiment. 
         FIG. 18  is a schematic configuration diagram of a projector according to a sixth embodiment. 
         FIG. 19  is a perspective view showing a first example of a light guide. 
         FIG. 20  is a perspective view showing a second example of the light guide. 
     
    
    
     DESCRIPTION OF EXEMPLARY EMBODIMENTS 
     First Embodiment 
     A first embodiment of the present disclosure will be described below with reference to  FIGS. 1 to 9 . 
       FIG. 1  is a schematic configuration diagram of a projector according to the present embodiment. 
     In the following drawings, components are drawn at different dimensional scales in some cases for clarity of each of the components. 
     A projector  10  according to the present embodiment is a projection-type image display apparatus that projects an image on a screen  11 , as shown in  FIG. 1 . The projector  10  includes a light emitting apparatus  12 , a light modulating apparatus  13 , and a projection optical apparatus  14 . The configuration of the light emitting apparatus  12  will be described later in detail. 
     An axis that coincides with a normal passing through the center of a light emission region  12 R of the light emitting apparatus  12  and serves an optical axis along which the chief ray of a light flux L emitted from the light emission region  12 R is hereinafter referred to as an optical axis AX 1 . Each of the apparatuses described above will be described below by using an XYZ orthogonal coordinate system. In the description, an axis X is an axis parallel to the long edges of the light emission region  12 R, which has a rectangular planar shape when viewed along the optical axis AX 1 , an axis Y is an axis parallel to the short edges of the light emission region, and an axis Z is the axis perpendicular to the axes X and Y. The axis Z is parallel to the optical axis AX 1 . 
     The light modulating apparatus  13  modulates the light flux L emitted from the light emitting apparatus  12  in accordance with image information to produce image light. The light modulating apparatus  13  includes a light-incident-side polarizer  16 , a liquid crystal display device  17 , and a light-exiting-side polarizer  18 . When viewed along the axis Z, an image formation region  17 R of the liquid crystal display device  17  has a rectangular planar shape. The light emission region  12 R of light emitting apparatus  12  has a rectangular planar shape, as described above, and the planar shape of the image formation region  17 R is similar to the planar shape of the light emission region  12 R. The area of the light emission region  12 R is equal to or slightly greater than the area of the image formation region  17 R. 
     The projection optical apparatus  14  projects the image light emitted from the light modulating apparatus  13  on a projection receiving surfaces, such as the screen  11 . The projection optical apparatus  14  is formed of one or more projection lenses. 
     The light emitting apparatus  12  will be described below. 
     The light emitting apparatus  12  includes a light emitter  20  and a heat sink  21 , as shown in  FIG. 1 . The light emitter  20  has a first surface  20   a  and a second surface  20   b  and emits the light flux L via the first surface  20   a . The heat sink  21  is provided on the second surface  20   b  of the light emitter  20  to dissipate heat generated in the light emitter  20 . 
       FIG. 2  is a plan view showing a schematic configuration of the light emitter  20 .  FIG. 3  is a plan view of a resonator  23 .  FIG. 4  is a cross-sectional view of the resonator  23  taken along the line IV-IV in  FIG. 3 .  FIG. 2  shows only part of the resonators  23  provided in the light emission region  12 R and does not show the other resonator  23  for ease of illustration. 
     The light emitter  20  includes a substrate  50  (base), a laminate  51 , a first electrode  52 , and second electrodes  53 , as shown in  FIG. 4 . The laminate  51  includes a reflection layer  55 , a buffer layer  56 , photonic crystal structures  57 , and third semiconductor layers  58 . 
     The substrate  50  is formed, for example, of a silicon (Si) substrate, a gallium nitride (GaN) substrate, or a sapphire substrate. 
     The reflection layer  55  is provided on the substrate  50 . The reflection layer  55  is formed, for example, of a distribution Bragg reflector (DBR) layer. The reflection layer  55  is formed, for example, of a laminate in which an AlGaN layer and a GaN layer are alternately layered on each other or an AlInN layer and a GaN layer are alternately layered on each other. The reflection layer  55  reflects light produced by light emitting layers  66 , which will be described later, of the photonic crystal structures  57  toward the second electrodes  53 . 
     In the present specification, the directions of the axis Z, which is the lamination direction of the laminate  51 , are defined with respect to the light emitting layers  66  as follows: The direction from the light emitting layers  66  toward second semiconductor layers  67  is “upper;” and the direction from the light emitting layers  66  toward first semiconductor layers  65  is “lower.” The “lamination direction of the laminate  51 ” is the direction in which the first semiconductor layers  65  face the light emitting layers  66  and is hereinafter simply referred to as the “lamination direction” in some cases. 
     The buffer layer  56  is provided on the reflection layer  55 . The buffer layer  56  is made of a semiconductor material and is formed, for example, of an n-type GaN layer into which Si has been doped. In the example shown in  FIG. 4 , a mask layer  60 , grows a film that forms columnar sections  62  in the process of manufacturing the light emitter  20 , which will be described later, is provided on the buffer layer  56 . The mask layer  60  is formed, for example, of a silicon oxide layer or a silicon nitride layer. 
     The photonic crystal structures  57  are each a columnar structure provided on the buffer layer  56 . The photonic crystal structures  57  include a plurality of columnar sections  62  and a plurality of light propagation layers  63 . The photonic crystal structures  57  can provide a photonic crystal effect, which causes the light emitted by the light emitting layers  66  to be confined in the in-plane directions of the substrate  50  and exit in the lamination direction. The “in-plane directions of the substrate  50 ” are directions along a plane perpendicular to the lamination direction. 
     The photonic crystal structures  57  each have, for example, a polygonal, circular, or elliptical planar shape. In the present embodiment, the photonic crystal structures  57  each have a regular hexagonal planar shape, as shown in  FIG. 3 . The photonic crystal structures  57  each have a diameter of the order of nanometers, specifically, a diameter greater than or equal to 10 nm but smaller than or equal to 500 nm. The columnar sections  62  are nano-structures that form the photonic crystal structures  57 , as shown in  FIG. 4 . The dimension of the photonic crystal structures  57 , what is called a height H of the photonic crystal structures  57  is, for example, greater than or equal to 1 μm but smaller than or equal to 5 μm. 
     The “diameter of each of the photonic crystal structures  57 ” is defined as follows: In a case where the photonic crystal structures  57  have a circular planar shape, the diameter is the diameter of the circle; and when the photonic crystal structures  57  have a non-circular planar shape, the diameter is the diameter of a minimum inclusion circle of the non-circular shape. For example, when the photonic crystal structures  57  have a polygonal planar shape, the diameter is the diameter of the minimum circle containing the polygon therein, and when the photonic crystal structures  57  have an elliptical planar shape, the diameter is the diameter of the minimum circle containing the ellipse therein. 
     The “center of each of the photonic crystal structures  57 ” is defined as follows: In the case where the photonic crystal structures  57  have a circular planar shape, the center is the center of the circle; and when the photonic crystal structures  57  have a non-circular planar shape, the center is the center of the minimum inclusion circle of the non-circular shape. For example, when the photonic crystal structures  57  have a polygonal planar shape, the center of each of the photonic crystal structures  57  is the center of the minimum circle containing the polygon therein, and when the photonic crystal structures  57  have an elliptical planar shape, the center of each of the photonic crystal structures  57  is the center of the minimum circle containing the ellipse therein. 
     The plurality of photonic crystal structures  57  are arranged in the form of a square lattice on the buffer layer  56 , as shown in  FIG. 3 . The intervals Px and Py between adjacent two photonic crystal structures  57  are, for example, greater than or equal to 1 nm but smaller than or equal to 500 nm. In the present embodiment, the interval Px in the direction of the axis X and the interval Py in the direction of the axis Y are equal to each other. As described above, the plurality of photonic crystal structures  57  are periodically arranged at the predetermined intervals Px and Py along the directions of the axes X and Y perpendicular to each other. The interval Px in the direction of the axis X is the distance between the centers of photonic crystal structures  57  adjacent to each other in the direction of the axis X. The interval Py in the direction of the axis Y is the distance between the centers of photonic crystal structures  57  adjacent to each other in the direction of the axis Y. The plurality of photonic crystal structures  57  are not necessarily arranged in the form of a square lattice and may instead be arranged, for example, in the form of an oblong lattice or a triangular lattice. 
     The columnar sections  62  each include the first semiconductor layer  65 , the light emitting layer  66 , and the second semiconductor layer  67 , as shown in  FIG. 4 . 
     The first semiconductor layers  65  are provided on the buffer layer  56 . The first semiconductor layers  65  are each formed, for example, of an n-type GaN layer into which Si has been doped. 
     The light emitting layers  66  are provided on the first semiconductor layers  65 . The light emitting layers  66  are provided between the first semiconductor layers  65  and the second semiconductor layers  67 . The light emitting layers  66  each have a quantum well structure formed, for example, of a GaN layer and an InGaN layer. The light emitting layers  66  produce light when current is injected thereinto via the first semiconductor layer  65  and the second semiconductor layer  67 . 
     The second semiconductor layers  67  are provided on the light emitting layers  66 . The second semiconductor layers  67  are layers different from the first semiconductor layers  65  in terms of conductivity type. The second semiconductor layers  67  are each, for example, a p-type GaN layer into which Mg has been doped. The first semiconductor layer  65  and the second semiconductor layer  67  function as cladding layers having the function of confining the light in the light emitting layers  66 . 
     The light propagation layers  63  are provided between adjacent columnar sections  62 . In the example shown in  FIG. 4 , the light propagation layers  63  are provided on the mask layer  60 . The refractive index of the light propagation layers  63  is lower than the refractive index of the light emitting layers  66 . The light propagation layers  63  are each formed, for example, of a silicon oxide layer, an aluminum oxide layer, or a titanium oxide layer. The light produced in the light emitting layers  66  propagates through the light propagation layers  63 . 
     The resonators  23  are each formed of a plurality of photonic crystal structures  57  arranged in the form of a square lattice, as shown in  FIG. 3 . A plurality of resonators  23  are so disposed on a first surface  50   a  of the substrate  50  as to be separate from each other, as shown in  FIG. 2 . That is, no photonic crystal structure  57  is provided between adjacent resonators  23 . The plurality of resonators  23  form the light emission region  12 R, which emits light that the periodic structure of each of the photonic crystal structures  57  causes to resonate. 
     In adjacent two resonators  23 , the light that resonates in one of the resonators  23  does not reach the other resonator  23 . A distance G between resonators  23  adjacent to each other is greater than the wavelength of the light produced in the light emitting layers  66 . The thus configured resonators  23  allow the light that resonates in one of resonators  23  adjacent to each other not to reach the other resonator  23 . 
     Light absorbers that absorb light may be provided between adjacent resonators  23 . The light absorbers are made of a material having a bandgap narrower than the bandgap corresponding to the light that resonates in the resonators  23 . Materials of this type may include InGaN and InN. The light absorbers are each formed, for example, of a columnar or wall-shaped crystal provided between adjacent resonators  23 . The light absorbers allow the light that resonates in one of resonators  23  adjacent to each other not to reach the other resonator  23 . 
     Instead, light reflectors that reflect light may be provided between adjacent resonators  23 . For example, the light reflectors can be formed by providing columnar structures between adjacent resonators  23 , the columnar structures arranged at intervals smaller than the intervals at which the photonic crystal structures  57 , which form each of the resonators  23 , are arranged or the columnar structures having a diameter smaller than the diameter of the photonic crystal structures  57 . The thus configured light absorbers allow the light that resonates in one of resonators  23  adjacent to each other not to reach the other resonator  23 . 
     In the light emitting apparatus  12 , a laminate of each of the p-type second semiconductor layers  67 , the light emitting layers  66  into which no impurity has been doped, and the n-type first semiconductor layers  65  forms a pin diode. The bandgaps of the first semiconductor layer  65  and the second semiconductor layer  67  is wider than the bandgap of the light emitting layer  66 . When forward bias voltage for the pin diode is applied to the gap between the first electrode  52  and the second electrodes  53 , current is injected into the light emitting layers  66 , resulting in electron-hole recombination in the light emitting layers  66 , followed by the light emission. 
     The first semiconductor layers  65  and the second semiconductor layers  67  cause the light produced in the light emitting layers  66  to propagate through the light propagation layers  63  in the in-plane directions of the substrate  50 . In this process, the light forms a standing wave due to the photonic crystal effect provided by the photonic crystal structures  57  and is confined in the in-plane directions of the substrate  50 . The confined light receives gain in the light emitting layers  66 , resulting in laser oscillation. That is, the photonic crystal structures  57  cause the light produced in the light emitting layers  66  to resonate in the in-plane directions of the substrate  50 , resulting in laser oscillation. Specifically, the light produced in the light emitting layers  66  resonates in the in-plane directions of the substrate  50  in the resonators  23  each formed of the plurality of photonic crystal structures  57 , resulting in laser oscillation. Thereafter, ±1st-order diffracted light produced by the resonance travels as laser light in the lamination direction (direction of axis Z). 
     Out of the laser light having traveled in the lamination direction, the laser light having traveled toward the reflection layer  55  is reflected off the reflection layer  55  and travels toward the second electrodes  53 . The light emitting apparatus  12  can thus emit the light via the second electrodes  53 . 
     The third semiconductor layers  58  are provided on the photonic crystal structures  57 . The third semiconductor layers  58  are each formed, for example, of a p-type GaN layer into which Mg has been doped. 
     The first electrode  52  is provided on the buffer layer  56  on a side of the photonic crystal structures  57 . The first electrode  52  may be in ohmic contact with the buffer layer  56 . In the example shown in  FIG. 3 , the first electrode  52  is electrically coupled to the first semiconductor layers  65  via the buffer layer  56 . The first electrode  52  is one of the electrodes via which current is injected into the light emitting layers  66 . The first electrode  52  is, for example, a laminate film of a Ti layer, an Al layer, and an Au layer layered in this order from the side facing the buffer layer  56 . 
     The second electrodes  53  are provided on the third semiconductor layers  58 . The second electrodes  53  may be in ohmic contact with the third semiconductor layers  58 . The second electrodes  53  are electrically coupled to the second semiconductor layers  67 . In the example shown in  FIG. 4 , the second electrodes  53  are electrically coupled to the second semiconductor layers  67  via the third semiconductor layers  58 . The second electrodes  53  are the other one of the electrodes via which current is injected into the light emitting layers  66 . The second electrodes  53  are made, for example, of ITO (indium tin oxide). The second electrode  53  provided at one of adjacent photonic crystal structures  57  is electrically coupled via wiring that is not shown to the second electrode  53  provided at the other photonic crystal structure  57 . 
       FIG. 5  shows the light orientation angle of light L 0  emitted from each of the resonators  23 . 
     An axis-X-direction length Dx of the resonator  23  is equal to an axis-Y-direction length Dy of the resonator  23  in the plan view, as shown in  FIG. 3 . When the lengths Dx and Dy of the resonator  23  is equal to each other as described above, an axis-X-direction light orientation angle θx of the light L 0  emitted from the resonator  23  is equal to an axis-Y-direction light orientation angle θy of the light L 0 , as shown in  FIG. 5 . Conversely, comparison between the axis-X-direction light orientation angle θx of the light L 0  emitted from the resonator  23  and the axis-Y-direction light orientation angle θy of the light L 0  allows checking of whether or not the lengths Dx and Dy are equal to each other. When the resonators  23  have a rotationally symmetric planar shape, such as a square or a regular hexagonal shape, the light orientation angle of the light L 0  emitted from each of the resonators  23  is rotationally symmetric with respect to an optical axis AX 0 . The light orientation angle is defined as the angle between the outermost light ray emitted from one light emission point O and a normal passing through the light emission point O. 
     In the plan view, the outer shape of each of the resonators  23  is a square corresponding to the figure surrounded by the straight lines that connect the centers of the photonic crystal structures  57  located at the outermost circumference out of the plurality of photonic crystal structures  57  that form the resonator  23 , as shown in  FIG. 3 . In each of the resonator  23 , the light emitted from the light emitting layer  66  resonates in each of the directions of the axes X and Y along which the plurality of photonic crystal structures  57  are arranged at the fixed intervals in the resonator  23 . That is, the light L 0  resonates in two resonance directions. 
     The axis-X-direction resonant length of each of the resonators  23  corresponds to the length Dx of the straight line that connects the centers of the plurality of photonic crystal structures  57  arranged in a row in the direction of the axis X. Similarly, the axis-Y-direction resonant length of the resonator  23  corresponds to the length Dy of the straight line that connects the centers of the plurality of photonic crystal structures  57  arranged in a row in the direction of the axis Y. In the present embodiment, since the resonators  23  each have a square outer shape, the axis-X-direction resonance length of each of the resonators  23  is equal to the axis-Y-direction resonance length of the resonator  23 . The axis-X-direction length Dx and the axis-Y-direction length Dy of each of the resonators  23  are hereinafter collectively referred to as the size of the resonator  23  in some cases. 
     In the light emission region  12 R, the sizes Dx and Dy of the plurality of resonators  23  gradually increase with distance from a central portion of the light emission region  12 R toward a peripheral portion thereof, as shown in  FIG. 2 . In other words, the axis-X-direction resonance length and the axis-Y-direction resonance length of the plurality of resonators  23  gradually increase with distance from the central portion of the light emission region  12 R toward the peripheral portion thereof. The diameter and height of the photonic crystal structures  57  provided in each of the resonators  23 , the intervals at which the photonic crystal structures  57  are arranged, the arrangement of the photonic crystal structures  57 , and other parameters thereof are the same in all the resonators  23 . 
     Now assume that an arbitrary resonator  23  located in a position close to the central portion of the light emission region  12 R is called a first resonator  23 A, and that an arbitrary resonator  23  located in a position farther from the central portion of the light emission region  12 R than the first resonator  23 A is called a second resonator  23 B. That is, the plurality of resonators  23  include the first resonator  23 A and the second resonator  23 B. 
     For example, it is assumed in  FIG. 2  that the resonator  23  located at the center of the light emission region  12 R is the first resonator  23 A, and that the fourth resonator  23  counted from the resonator located at the center of the light emission region  12 R is the second resonator  23 B. Under the definition described above, the distance from the center of the light emission region  12 R to the second resonator  23 B is longer than the distance from the center of the light emission region  12 R to the first resonator  23 A, and the resonance length of the second resonator  23 B is longer than the resonance length of the first resonator  23 A. 
     In the present embodiment, the plurality of resonators  23  located at the same distance from the center of the light emission region  12 R have the same resonance length. In  FIG. 2 , a curve that connects the plurality of resonators  23  having the same resonance length to each other is shown in the form of a circle drawn with a two-dot chain line. There are a large number of such circles, and  FIG. 2  shows only three such circles. 
     In the present embodiment, a plurality of resonators  23  having the same resonance length are arranged concentrically around the center of the light emission region  12 R. That is, the ratio of the amount of change in the resonance length of a resonator  23  to the amount of change in the distance from the center of the light emission region  12 R to the resonator  23  is fixed in all the directions viewed from the center of the light emission region  12 R. A plurality of resonators  23  having the same resonance length may instead be arranged, for example, in the form of concentric rectangles or concentric ellipses around the center of the light emission region  12 R. That is, the ratio of the amount of change in the resonance length of a resonator  23  to the amount of change in the distance from the center of the light emission region  12 R to the resonator  23  may vary among the directions viewed from the center of the light emission region  12 R. 
     Due to a photonic crystal effect, the size, that is, the resonance length of a resonator  23  affects the light orientation angle of the light L 0  emitted from the resonator  23 . Specifically, the greater the size of a resonator  23 , the smaller the light orientation angle of the light L 0  emitted from the resonator  23 , whereas the smaller the size of a resonator  23 , the greater the light orientation angle of the light L 0  emitted from the resonator  23 . 
       FIG. 6  shows the light orientation angles of the light L 0  emitted from a plurality of resonators  23  located in positions P 1 , P 2 , P 3 , and P 4  different from one another in the light emission region  12 R.  FIG. 6  shows only the light L 0  emitted from the resonators  23  located in the four positions P 1 , P 2 , P 3 , and P 4  arranged along the direction of the axis X out of the large number of resonators  23  present in the light emission region  12 R. 
     In the present embodiment, the size, that is, the resonance length of the resonators  23  gradually increases with distance from the center of the light emission region  12 R toward the periphery thereof, as described above. Let θ 1  be the light orientation angle of the light L 0  emitted from the resonator  23  in the position P 1 , θ 2  be the light orientation angle of the light L 0  emitted from the resonator  23  in the position P 2 , θ 3  be the light orientation angle of the light L 0  emitted from the resonator  23  in the position P 3 , and θ 4  be the light orientation angle of the light L 0  emitted from the resonator  23  in the position P 4 , and the magnitudes of the light orientation angles θ 1  to θ 4  are expressed as follows: θ 1 &gt;θ 2 &gt;θ 3 &gt;θ 4 , as shown in  FIG. 6 . That is, the light orientation angles of the light L 0  emitted from the resonators  23  gradually decrease with distance from the center of the light emission region  12 R toward the periphery thereof. 
       FIG. 7  shows the positions where the light L 0  emitted from the positions P 1 , P 2 , P 3 , and P 4  in  FIG. 6  reaches the image formation region  17 R of the liquid crystal display device  17 . 
     The light flux L emitted from the light emitting apparatus  12  travels via the light-incident-side polarizer  16  and is incident on the image formation region  17 R of the liquid crystal display device  17  disposed in a position separate from the light emitting apparatus  12  by a distance Z 1 . Let Q 1 , Q 2 , Q 3 , and Q 4  be the positions where the light L 0  emitted from the resonators  23  in the positions P 1 , P 2 , P 3 , and P 4  reaches the image formation region  17 R, and let R 1 , R 2 , R 3 , and R 4  be the distances from a center O 1  of the image formation region  17 R to the positions Q 1 , Q 2 , Q 3 , and Q 4 , and the magnitudes of the distances are desirably expressed by R 1 &lt;R 2 &lt;R 3 &lt;R 4 . In other words, it is desirable that the position where the light L 0  emitted from a resonator  23  close to the center of the light emission region  12 R reaches is not beyond but is within the position where the light L 0  emitted from a resonator  23  located in a position far from the center of the light emission region  12 R. 
     Now, consider a light emitting apparatus according to Comparative Example in which the light emission region has a plurality of resonators having the same size (resonance length). It is assumed that the light emission region has a square planar shape. 
       FIG. 9  shows the cross-sectional shape perpendicular to the chief ray of a light flux L 3  and the intensity distribution of the light flux L 3  in an illumination receiving region of the light emitting apparatus according to Comparative Example. The upper portion of  FIG. 9  shows the cross-sectional shape of the light flux L 3 , and the lower portion of  FIG. 9  shows the intensity distribution of the light flux. The upper portion of  FIG. 9  further shows intensity contour lines (iso-intensity lines) in addition to the cross-sectional shape of the light flux L 3 . 
     In the light emitting apparatus according to Comparative Example, the cross-sectional shape of the light flux L 3  emitted from the square light emission region changes from the square to a shape having rounded corners, as shown in  FIG. 9 . Further, the intensity distribution of the light flux L 3  is so shaped that the intensity is high at the center of the illumination receiving region and low at the periphery thereof, and that the intensity greatly varies depending on the position in the illumination receiving region. 
     In contrast,  FIG. 8  shows the cross-sectional shape perpendicular to the chief ray of the light flux L and the intensity distribution of the light flux Lin the illumination receiving region in the light emitting apparatus  12  according to the present embodiment. The upper portion of  FIG. 8  shows the cross-sectional shape of the light flux L, and the lower portion of  FIG. 8  shows the intensity distribution of the light flux L. The upper portion of  FIG. 8  further shows intensity contour lines (iso-intensity lines) in addition to the cross-sectional shape of the light flux. The broken lines in the upper and lower portions of  FIG. 8  represent the cross-sectional shape and the intensity distribution of the light flux L immediately after the light flux Lis emitted from the light emitting apparatus  12 . It is assumed in the description that the light emission region  12 R has a square planar shape for comparison with Comparative Example. 
     In the light emitting apparatus  12  according to the present embodiment, the cross-sectional shape of the light flux L emitted from the light emission region  12 R has corners that are not greatly rounded, unlike in Comparative Example, but does not greatly differ from the square, as shown in  FIG. 8 . Further, the light emitted from the central portion of the light emission region  12 R greatly spreads, but the light emitted from the peripheral portion of the light emission region  12 R does not greatly spread. The intensity distribution of the light flux L emitted from the light emission region  12 R is therefore so shaped that the intensity is slightly higher at the peripheral portion of the light emission region  12 R than that in the central portion, but that a substantially uniform intensity distribution is provided irrespective of the position in the illumination receiving region. As described above, the cross-sectional shape and the intensity distribution of the light flux L immediately after the light flux L is emitted from the light emitting apparatus  12  are sufficiently maintained even in the illumination receiving region. 
     As described above, the light emitting apparatus  12  according to the present embodiment, in which the plurality of resonators  23  have different resonance lengths so that the light orientation angle varies in accordance with the position in the light emission region  12 R, can control the cross-sectional shape and the intensity distribution of the light flux L in the illumination receiving region separate from the light emitting apparatus  12 . In the present embodiment, in particular, since the light orientation angle of the light emitted from a resonator  23  located at the peripheral portion of the light emission region  12 R is smaller than the light orientation angle of the light emitted from a resonator  23  located in the central portion of the light emission region  12 R, the cross-sectional shape of the light flux L immediately after the light flux L is emitted from the light emitting apparatus  12  can be sufficiently maintained even in the image formation region  17 R of the liquid crystal display device  17  separate from the light emitting apparatus  12 . 
     The thus configured light emitting apparatus  12  according to the present embodiment, which allows the cross-sectional shape of the light flux L emitted therefrom to be substantially match with the shape of the image formation region  17 R, can efficiently illuminate the light modulating apparatus  13 . It is noted that the cross-sectional shape of the light flux L changes depending on the light orientation angle and the distribution of the light flux L emitted from the light emitting apparatus  12 , the intensity and the distribution of the light flux L, the distance from the light emitting apparatus  12 , and other factors. 
     Since the projector  10  according to the present embodiment includes the light emitting apparatus  12  that provides the effect described above, the light can be used efficiently, and the size of the projector  10  can be reduced. 
     Second Embodiment 
     A second embodiment of the present disclosure will be described below with reference to  FIG. 10 . 
     The basic configuration of the light emitting apparatus according to the second embodiment is the same as that in the first embodiment, and the second embodiment differs from the first embodiment in terms of the configuration of the plurality of resonators. No description of the entire light emitting apparatus will therefore be made. 
       FIG. 10  is a plan view of the light emitting apparatus according to the second embodiment. 
     In  FIG. 10 , the components common to those in  FIG. 2  used in the description of the first embodiment have the same reference characters and will not be described. 
     In a light emitting apparatus  30  according to the present embodiment, a light emission region  30 R is divided into a plurality of rectangular divided regions concentric around the center of the light emission region  30 R, as shown in  FIG. 10 . In the present embodiment, the plurality of divided regions include five divided regions, a first divided region  30 R 1 , a second divided region  30 R 2 , a third divided region  30 R 3 , a fourth divided region  30 R 4 , and a fifth divided region  30 R 5 , sequentially arranged from the center of the light emission region  30 R. The “divided regions” in the present disclosure do not mean that a component of the light emitting apparatus  30  is physically divided but means separate regions in the light emission region  30 R in each of which a plurality of resonators  23  having the same size are disposed, as will be described later. 
     The plurality of resonators  23  include a plurality of first resonators  23 A, a plurality of second resonators  23 B, a plurality of third resonators  23 C, a plurality of fourth resonators  23 D, and a plurality of fifth resonators  23 E. The plurality of first resonators  23 A are provided in the first divided region  30 R 1 . The plurality of second resonators  23 B are provided in the second divided region  30 R 2 . The plurality of third resonators  23 C are provided in the third divided region  30 R 3 . The plurality of fourth resonators  23 D are provided in the fourth divided region  30 R 4 . The plurality of fifth resonators  23 E are provided in the fifth divided region  30 R 5 . 
     Also in the present embodiment, in which the resonators  23  each have a square planar shape, the axis-X-direction length Dx of each of the resonators  23  is equal to the axis-Y-direction length Dy of the resonator  23 , as in the first embodiment. The axis-X-direction length Dx and the axis-Y-direction length Dy of each of the resonators  23  are therefore collectively referred to as the size of the resonator  23  in the description. Let L 1  be the size of the first resonators  23 A, L 2  be the size of the second resonators  23 B, L 3  be the size of the third resonators  23 C, L 4  be the size of the fourth resonators  23 D, and L 5  be the size of the fifth resonators  23 E. 
     The size of the plurality of resonators  23 , that is, the resonance length increases with distance from the center of the light emission region  30 R toward the periphery thereof. The size of the resonators  23  is expressed as follows: L 1 &lt;L 2 &lt;L 3 &lt;L 4 &lt;L 5 . The plurality of first resonators  23 A in the first divided region  30 R 1  have the same size, that is, resonance length. The plurality of second resonators  23 B in the second divided region  30 R 2  have the same size, that is, resonance length. The plurality of third resonators  23 C in the third divided region  30 R 3  have the same size, that is, resonance length. The plurality of fourth resonators  23 D in the fourth divided region  30 R 4  have the same size, that is, resonance length. The plurality of fifth resonators  23 E in the fifth divided region  30 R 5  have the same size, that is, resonance length. 
     In the light emitting apparatus  12  according to the first embodiment, the light emission region  12 R is not divided, and the size, that is, the resonance length of the plurality of resonators  23  continuously increases with distance from the central portion of the light emission region  12 R toward the peripheral portion thereof. In contrast, in the light emitting apparatus  30  according to the present embodiment, the light emission region  30 R is divided into the plurality of divided regions  30 R 1 ,  30 R 2 ,  30 R 3 ,  30 R 4 , and  30 R 5 , and the closer a divided region to the periphery of the light emission region  30 R, the greater the size of the resonators  23  in the divided region, that is, the longer the resonance length, and the plurality of resonators  23  in each of the divided regions have the same size, that is, resonance length. Simply speaking, in the light emitting apparatus  30  according to the present embodiment, the size, that is, the resonance length of the plurality of resonators  23  increases stepwise with distance from the central portion of the light emission region  30 R toward the peripheral portion thereof. 
     The other configurations of the light emitting apparatus  30  are the same as those in the first embodiment. 
     The light emitting apparatus  30  according to the present embodiment, which allows the shape of the light flux to substantially match with the shape of the image formation region, also provides the same effect provided by the first embodiment, for example, the light modulating apparatus can be efficiently illuminated. 
     Further, in the present embodiment, since the separate divided regions  30 R 1 ,  30 R 2 ,  30 R 3 ,  30 R 4 , and  30 R 5  are each formed of the resonators  23  having the same size, the plurality of resonators  23  are likely to be arranged at a high density in the light emission region  30 R, as compared with the light emitting apparatus  12  according to the first embodiment. The packing ratio of the resonators  23  per light emission area can thus be increased, whereby the light emission density can be increased. 
     In the present embodiment, the light emission region  30 R is divided into the five divided regions  30 R 1 ,  30 R 2 ,  30 R 3 ,  30 R 4 , and  30 R 5  and may be divided into a larger number of divided regions. The larger the number of divided regions, the closer the characteristics of the light emitting apparatus  30  to those in the first embodiment, in which the resonance length continuously changes. 
     Variation 
       FIG. 11  shows the relationship between the distance from the center of the light emission region and the size of the resonators. In  FIG. 11 , the horizontal axis represents the distance from the center of the light emission region, and the vertical axis represents the size, that is, the resonance length of the resonators. 
     In  FIG. 11 , the graphs labeled with reference characters A and B correspond to the light emitting apparatus  12  according to the first embodiment, and the size of the resonators continuously changes in accordance with a change in the distance from the center of the light emission region. In this case, the ratio of the amount of change in the size of the resonators to the amount of change in the distance from the center of the light emission region may be fixed irrespective of the distance from the center of the light emission region, as indicated by the graph labeled with the reference character A, or may change in accordance with the distance from the center of the light emission region, as indicated by the graph labeled with the reference character B. 
     In  FIG. 11 , the graph labeled with a reference character C corresponds to the light emitting apparatus  30  according to the second embodiment, and the size of the resonators changes stepwise in accordance with the distance from the center of the light emission region. Further, the size of the resonators may locally decrease as the positions of the resonators are shifted away from the central portion of the light emission region, as indicated by a graph labeled with a reference character D. As described above, the size of the resonators may not necessarily monotonously increase in accordance with an increase in the distance from the center of the light emission region, and the size of the resonators closer to the periphery of the light emission region only needs to be greater than the size of the resonators closer to the center of the light emission region when the light emission region is taken as a whole. 
     Third Embodiment 
     A third embodiment of the present disclosure will be described below with reference to  FIG. 12 . 
     The basic configuration of a light emitting apparatus according to the third embodiment is the same as that in the first embodiment but differs from the first embodiment in terms of the configuration of the base. No description will therefore be made of the entire light emitting apparatus. 
       FIG. 12  is a cross-sectional view of a light emitting apparatus  40  according to the third embodiment. 
     In  FIG. 12 , the components common to those in the figures used in the description of the first embodiment have the same reference characters and will not be described. 
     The light emitting apparatus  40  according to the present embodiment includes the substrate  50  (base), intermediate substrates  41  (intermediate bases), the laminate  51 , the first electrode (not shown), and the second electrodes  53 , as shown in  FIG. 12 . The laminate  51  includes the reflection layers  55 , the buffer layers  56 , the photonic crystal structures  57  (columnar structures), and the third semiconductor layers  58 . The detailed configuration of the photonic crystal structures  57  is the same as that of the photonic crystal structures  57  in the first embodiment shown in  FIG. 4 . Although not shown, wiring is formed in each of the substrate  50  and the intermediate substrates  41 , and the second electrodes  53  are electrically coupled to the wiring in the substrate  50  via the wiring formed in the intermediate substrates  41 . The first electrode is electrically coupled to the wiring in the substrate  50 , for example, via the wiring formed in the intermediate substrates  41 . The first electrode may instead be electrically coupled to the wiring in the substrate  50  via the rear surfaces of the intermediate substrates  41 . 
     In the present embodiment, the plurality of resonators  23  are provided on the first surface  50   a  of the substrate  50  via the plurality of intermediate substrates  41 . That is, the plurality of intermediate substrates  41  are provided on the first surface  50   a  of the substrate  50 , and the plurality of resonators  23  are each provided on the corresponding one of the plurality of intermediate substrates  41 . The plurality of intermediate substrates  41  include a first intermediate substrate  41 A (first intermediate base) and second intermediate substrates  41 B (second intermediate bases). 
     It is assumed as in the first embodiment that the resonator  23  located at the center O of the light emission region  12 R is called the first resonator  23 A, and that a resonator  23  located in a position separate from the center O of the light emission region  12 R is called the second resonator  23 B. The distance from the center of the light emission region  12 R to the second resonator  23 B is longer than the distance from the center of the light emission region  12 R to the first resonator  23 A, and the resonance length of the second resonator  23 B is longer than the resonance length of the first resonator  23 A. In the present embodiment, the size, that is, the resonance length of the resonators  23  gradually increases with distance from the center of the light emission region  12 R toward the periphery thereof, as shown in  FIG. 4 , which has been used in the description of the first embodiment. 
     In the present embodiment, the first resonator  23 A is provided on the first intermediate substrate  41 A, and the second resonator  23 B is provided on the second intermediate substrate  41 B. That is, the first resonators  23 A and the second resonators  23 B are provided on intermediate substrates  41 A and  41 B different from each other. 
     The intermediate substrates  41  are made, for example, of silicon (Si), gallium nitride (GaN), sapphire, or any other material. The substrate  50  is made, for example, of silicon (Si), gallium nitride (GaN), sapphire, aluminum nitride (AlN), silicon carbide (SiC), or any other material. 
     The other configurations of the light emitting apparatus  40  are the same as those in the first embodiment. 
     The present embodiment, which allows the shape of the light flux to substantially match with the shape of the image formation region, also provides the same effect provided by the first embodiment, that is, the light modulating apparatus can be efficiently illuminated. 
     Further, according to the configuration of the present embodiment, the steps of manufacturing the light emitting apparatus  40  can be carried out in accordance with a method for forming the resonators  23  on the intermediate substrates  41  and then transferring the resonators  23  along with the intermediate substrates  41  to predetermined positions on the substrate  50 . The light emitting apparatus  40  can thus be efficiently manufactured at a high yield. 
     Fourth Embodiment 
     A fourth embodiment of the present disclosure will be described below with reference to  FIG. 13 . 
     The basic configuration of a light emitting apparatus according to the fourth embodiment is the same as that in the second embodiment but differs from the second embodiment in terms of the configuration of the base. No description will therefore be made of the entire light emitting apparatus. 
       FIG. 13  is a cross-sectional view of a light emitting apparatus  43  according to the fourth embodiment. 
     In  FIG. 13 , the components common to those in the figures used in the description of the above embodiments have the same reference characters and will not be described. 
     The plurality of resonators  23  are provided on the first surface  50   a  of the substrate  50  via the plurality of intermediate substrates  41  also in the light emitting apparatus  43  according to the present embodiment, as shown in  FIG. 13 , as in the third embodiment. That is, the plurality of intermediate substrates  41  are provided on the first surface  50   a  of the substrate  50 , and the plurality of resonators  23  are each provided on the corresponding one of the plurality of intermediate substrates  41 . The plurality of intermediate substrates  41  include the first intermediate substrate  41 A (first intermediate base) and the second intermediate substrates  41 B (second intermediate bases). Also in the present embodiment, although not shown, wiring is formed in each of the substrate  50  and the plurality of intermediate substrates  41 , and the second electrodes  53  are electrically coupled to the wiring in the substrate  50  via the wiring formed in the plurality of intermediate substrates  41 . The first electrode is electrically coupled to the wiring in the substrate  50 , for example, via the wiring formed in the intermediate substrates  41 . The first electrode may instead be electrically coupled to the wiring in the substrate  50  via the rear surfaces of the plurality of intermediate substrates  41 . 
     In the present embodiment, as shown in  FIG. 10 , as in the second embodiment, the light emission region  30 R has the plurality of divided regions  30 R 1  and  30 R 2 . In the present embodiment, the plurality of divided regions include the first divided region  30 R 1  and the second divided region  30 R 2  sequentially arranged from the center O of the light emission region  30 R. The plurality of resonators  23  include the plurality of first resonators  23 A and the plurality of second resonators  23 B. The plurality of first resonators  23 A are provided in the first divided region  30 R 1 . The plurality of second resonators  23 B are provided in the second divided region  30 R 2 . The size, that is, the resonance length of the plurality of resonators  23  increases stepwise with distance from the central portion of the light emission region  30 R toward the peripheral portion thereof. 
     In the present embodiment, the number of first intermediate substrates  41 A provided in the first divided region  30 R 1  is equal to the number of first resonators  23 A. That is, one first resonator  23 A is provided on one first intermediate substrate  41 A. Similarly, the number of second intermediate substrates  41 B provided in the second divided region  30 R 2  is equal to the number of second resonators  23 B. One second resonator  23 B is provided on one second intermediate substrate  41 B. 
     The other configurations of the light emitting apparatus  43  are the same as those in the first embodiment. 
     The present embodiment, which allows the shape of the light flux to substantially match with the shape of the image formation region, also provides the same effect provided by the first embodiment, for example, the light modulating apparatus can be efficiently illuminated. The present embodiment further provides the same effect provided by the third embodiment, that is, the resonators  23  are formed on the intermediate substrates  41 , the intermediate substrates  41  are then cut, and the resonators  23  along with the intermediate substrates  41  are transferred to predetermined positions on the substrate  50 , whereby the light emitting apparatus  43  can thus be efficiently manufactured at a high yield. 
     The light emitting apparatus  43  according to the present embodiment may have the configuration of a variation shown below.  FIG. 14  is a cross-sectional view of a light emitting apparatus  45  according to the variation. 
     In the light emitting apparatus  45  according to the variation, the plurality of first resonators  23 A are provided on one first intermediate substrate  41 C, and the plurality of second resonators  23 B are provided on one second intermediate substrate  41 D, as shown in  FIG. 14 . That is, in the light emitting apparatus  45  according to the variation, the plurality of resonators  23  having the same size are provided on one intermediate substrate  41 . A gap is provided between adjacent resonators  23  to separate the resonators  23 . The second electrodes  53 , which are located on the photonic crystal structures  57 , are electrically coupled to each other between adjacent resonators  23 . 
     As the configurations of the first and second electrodes, the following two configuration examples may be employed. 
       FIG. 15  is a cross-sectional view of a light emitting apparatus  47  showing a first configuration example of the electrodes. 
     In the light emitting apparatus  47  according to the first configuration example, the second electrode  53  (p electrode) is formed on the upper surface of the photonic crystal structure  57  via the third semiconductor layer  58 , as shown in  FIG. 15 . A first electrode  71  (n electrode) is formed on the intermediate substrate  41  via the reflection layer  55  and the buffer layer  56 . The first electrode  71  (n electrode) is electrically coupled to wiring  72  formed on the lateral side of the intermediate substrate  41 . Adjacent second electrodes  53  are electrically coupled to each other via wiring that is not shown but is formed, for example, of an ITO layer. The first electrode and the wiring  72  can be coupled to each other, for example, by patterning a metal film in a lift-off method. 
       FIG. 16  is a cross-sectional view of a light emitting apparatus  49  showing a second configuration example of the electrodes. 
     The light emitting apparatus  49  according to the second configuration example differs from the light emitting apparatus  47  according to the first configuration example in terms of position of the first electrode (n electrode), as shown in  FIG. 16 . In the second configuration example, an intermediate substrate  74  is made of an electrically conductive material, for example, n-type GaN to which Si has been doped. The reflection layer  55  is an n-type reflection layer having electrical conductivity and formed of a DBR layer made, for example, of n-type GaN/AlInN to which Si has been doped. The intermediate substrate  74  can thus have the function of the first electrode (n electrode). The buffer layer  56  is formed of an n-type GaN layer to which Si has been doped. The intermediate substrate  74  is disposed on wiring  73  formed on the substrate  50 . In the second configuration example, the substrate  50  needs to be an insulating substrate, such as an AlN substrate and an SiC substrate. 
     In the second configuration example, different from the first configuration example, no wiring  72  coupled to the first electrode needs to be formed along the thickness direction of the intermediate substrate  41 . The structure used to mount the intermediate substrate  74  on the substrate  50  and how to mount the intermediate substrate  74  on the substrate  50  can therefore be simplified. The light emitters can be arranged at an increased density, whereby a light emitting apparatus having a high light flux density can be provided. 
     Fifth Embodiment 
     Fifth and sixth embodiments will be described below about other configuration examples of the projector that can use any of the light emitting apparatuses according to the present disclosure. 
     The basic configuration of the projectors according to the fifth and sixth embodiments is the same as that of the projector according to the first embodiment. Therefore, no description will be made of the basic configuration, and only different portions will be described. 
       FIG. 17  is a schematic configuration diagram of the projector according to the fifth embodiment. 
     In  FIG. 17 , the components common to those in  FIG. 1  used in the description of the first embodiment have the same reference characters and will not be described. 
     A projector  32  according to the fifth embodiment further includes a relay system  33 , which is provided between the light emitting apparatus  12  and the light modulating apparatus  13 , as shown in  FIG. 17 . The relay system  33  includes a light-incident-side lens  34 , a relay lens  35 , and a light-exiting-side lens  36 . The light-incident-side lens  34  and the light-exiting-side lens  36  are configured to be optically conjugate with each other. The thus configured relay system  33  transmits the light flux image incident on the light-incident-side lens  34 , that is, the intensity distribution of the light flux L to the light-exiting-side lens  36  in such a way that the intensity distribution remains unchanged in terms of size or is enlarged or reduced, and emits the resultant light flux image via the light-exiting-side lens  36 .  FIG. 17  shows an example of the relay system  33  that enlarges the light flux image and transmits the enlarged light flux image. 
     The intensity distribution of the light flux L with which the image formation region  17 R of the liquid crystal display device  17  is illuminated is therefore substantially the same as the intensity distribution of the light flux L incident on the light-incident-side lens  34 . That is, to illuminate the image formation region  17 R of the liquid crystal display device  17  with a light flux having a cross-sectional shape that matches with that of the image formation region  17 R and has a substantially uniform intensity distribution, it is necessary to cause a light flux L having a size different from the size of the light flux incident on the image formation region  17 R but having the same cross-sectional shape and intensity distribution to be incident on the light-incident-side lens  34 . 
     In the projector  32  according to the present embodiment, which uses the light emitting apparatus  12  according to the embodiment described above, the light flux L is efficiently allowed to enter the relay system  33  disposed in a position separate from the light emitting apparatus  12 . 
     Providing the projector  32  with the relay system  33  allows a light flux having a size that matches with the size of the image formation region  17 R to be readily formed even when the size of the light emission region  12 R of the light emitting apparatus  12  greatly differs from the size of the image formation region  17 R of the liquid crystal display device  17 . Further, since the light modulating apparatus  13  can be disposed in a position separate from the light emitting apparatus  12 , the effect of the heat generated by the light emitting apparatus  12  on the light modulating apparatus  13  can be reduced. 
     In general, the light having passed through an optical system, such as the relay system  33 , suffers attenuation of the light at the periphery, resulting in high intensity in the vicinity of the optical axis AX 1  and a decrease in the intensity with distance from the optical axis AX 1 . When the light emitting apparatus  12  according to the embodiment described above is used, however, the intensity of the light emitted from the peripheral portion of the light emission region  12 R is higher than the intensity of the light emitted from the central portion of the light emission region  12 R, as shown in  FIG. 8 , whereby the effect of the light attenuation at the periphery due to the relay system  33  is reduced, and an image with only a small amount of brightness unevenness is likely to be produced. 
     Sixth Embodiment 
       FIG. 18  is a schematic configuration diagram of the projector according to the sixth embodiment.  FIG. 19  is a perspective view showing a first example of a light guide.  FIG. 20  is a perspective view showing a second example of the light guide. 
     In  FIG. 18 , the components common to those in  FIG. 1  used in the description of the first embodiment have the same reference characters and will not be described. 
     A projector  38  according to the sixth embodiment further includes a light guide  39  provided between the light emitting apparatus  12  and the light modulating apparatus  13 , as shown in  FIG. 18 . 
     As the light guide  39 , a light guide  39 A formed of a solid rod-shaped element made of a light transmissive medium, for example, glass is used, as shown in  FIG. 19 . Instead, a light guide  39 B formed of a hollow tubular element in which reflection mirrors are so disposed as to form a tube and cause the reflection surface to face inward is used as the light guide  39 , as shown in  FIG. 20 . In either case, a light guide having a light incident end and a light exiting end having the same opening size and shape may be used, or a light guide so tapered that the opening size increases from the light incident end toward the light exiting end or the opening size decreases from the light incident end toward the light exiting end may be used. 
     A light incident end  39   a  and a light exiting end  39   b  of the light guide  39  each have a rectangular opening so set as to be substantially similar to the light emission region  12 R of the light emitting apparatus  12  and the image formation region  17 R of the liquid crystal display device  17 . The size of the opening at the light incident end  39   a  of the light guide  39  is desirably equal to or slightly greater than the size of the light emission region  12 R. The size of the opening at the light exiting end  39   b  of the light guide  39  is desirably set to be equal to or slightly greater than the size of the image formation region  17 R of the liquid crystal display device  17 . 
     In the projector  38  according to the present embodiment, using the light emitting apparatus  12  according to any of the embodiments described above allows the light flux L to efficiently enter the light guide  39  disposed in a position separate from the light emitting apparatus  12 . 
     The light flux L having entered the light guide  39  is reflected off the interfaces or the inner wall surface of the light guide  39  multiple times and exits out of the light guide  39  with the intensity distribution of the light flux L homogenized. As a result, the intensity distribution of the light flux L is potentially further homogenized, whereby the liquid crystal display device  17  can be efficiently illuminated with the light flux L having the substantially uniform intensity. Further, since the light modulating apparatus  13  can be so disposed as to be separate from the light emitting apparatus  12 , the effect of the heat generated by the light emitting apparatus  12  on the light modulating apparatus  13  can be reduced. 
     The technical range of the present disclosure is not limited to those in the embodiments described above, and a variety of changes can be made to the embodiments to the extent that the changes do not depart from the substance of the present disclosure. 
     For example, in the embodiments described above, it is assumed that the light emitting apparatus emits a light flux having uniform intensity, and the present disclosure is also applicable to a light emitting apparatus that emits light having non-uniform intensity in the light emission region. The cross-sectional shape of the light flux can be controlled by changing the light orientation angle of the light emitted from each of the resonators in consideration of the intensity of the emitted light flux. 
     The aforementioned third and fourth embodiments have been described with reference to the case where the first resonator is provided on the first intermediate base and the second resonator is provided on the second intermediate base. In place of the configuration described above, a plurality of resonators including the first and second resonators may be provided on one intermediate base. In this case, using a high thermal conductivity substrate, for example, an AlN substrate and an SiC substrate, facilitates dissipation of the heat from the light emitters, whereby improvement in light emission efficiency and increase in the amount of emitted light can be expected. 
     The embodiments described above have been described with reference to the light emitting layer made of an InGaN-based material, and any of a variety of other semiconductor materials can be used in accordance with the wavelength of the emitted light. For example, an AlGaN-based, AlGaAs-based, InGaAs-based, InGaAsP-based, InP-based, GaP-based, or AlGaP-based semiconductor material can be used. Further, the diameter of the photonic crystal structures or the intervals at which the photonic crystal structures are arranged may be changed as appropriate in accordance with the wavelength of the emitted light. 
     In the embodiments described above, the photonic crystal structures are each formed of a columnar structure protruding from the substrate, and a plurality of holes may be provided at fixed intervals to provide the photonic crystal effect. That is, the plurality of resonators each only need to include photonic crystal structures each having a periodical structure irrespective of whether or not the columnar structure and holes are provided. 
     In addition to the above, the shape, the number, the arrangement, the material, and other factors of the components of the light emitting apparatus and the projector are not limited to those in the embodiments described above and can be changed as appropriate. In the embodiments described above, the light emitting apparatus according to the present disclosure is incorporated in a projector using a transmissive liquid crystal display device as the light modulating apparatus, but not necessarily. Any of the light emitting apparatuses according to the present disclosure may be incorporated in a projector using a reflective liquid crystal display device or a digital micromirror device as the light modulating apparatus. 
     Further, the above embodiments have been described with reference to the case where the light emitting apparatus according to the present disclosure is incorporated in a projector, but not necessarily. The light emitting apparatus according to the present disclosure may also be used as a lighting apparatus, a headlight of an automobile, and other components.