Patent Description:
There has been increasing interest in techniques using light (beam) for measuring the distance to an object or the direction of an object, recognizing an object or the topography of an area, or detecting information about the velocity, temperature, material distribution, etc. of an object. In this regard, research has been conducted into methods for adjusting the direction of light (beam) generated by a light source, that is, methods of beam steering.

Mechanical beam steering methods in which the direction of a beam is controlled by rotating some components, using a motor, have problems in terms of noise, size (volume), accuracy, etc. A typical non-mechanical beam steering method is a steering method using a micro-electro-mechanical system (MEMS) mirror. However, this method also has problems in terms of the field of view (FOV) and light transmitting distance.

Therefore, there is a need for techniques for improving performance indexes such as accuracy, precision, or speed in analysis and measurement, using a non-mechanical beam steering method.

<CIT> relates to an optical beam sweeper.

Example embodiments may address at least the above problems and/or disadvantages and other disadvantages not described above. Also, the example embodiments are not required to overcome the disadvantages described above, and may not overcome any of the problems described above.

Example embodiments provide beam steering devices configured to improve or increase the accuracy, precision, and speed of spatial analysis/measurement processes.

Example embodiments provide beam steering devices capable of scanning objects (subjects) at high speed.

Example embodiments provide beam steering devices capable of simultaneously emitting and steering a plurality of beams having multiple wavelengths.

Example embodiments provide optical apparatuses (for example, LiDAR apparatuses) including the beam steering devices.

According to an aspect of an example embodiment, there is provided a beam steering device according to claim <NUM>
The first direction may be parallel to an extension direction of the grating couplers, and the second direction may be perpendicular to the extension direction of the grating couplers.

The first direction may be parallel to an extension direction of the waveguides.

The optical modulator may include a phase modulator.

The light source may include laser sources or a multimode laser source, wherein the laser sources or the multimode laser source may be configured to generate lasers having the first different wavelengths as the generated input lights.

The light source may include a laser source configured to generate a laser having a wavelength, and a wavelength converter configured to divide the generated laser into lasers having the first different wavelengths as the generated input lights.

The light source may include a light emitting diode (LED) configured to generate light, and a multi-band pass filter configured to divide the generated light into the generated input lights.

Each of the generated input lights may have a pulse waveform.

Any one or any combination of the optical splitter, the optical modulator, and the emitter may include any one or any combination of a group IV element, a compound including a group IV element, a group III-V compound, an oxide, a nitride, and a polymer.

The beam steering device may further include an amplifier disposed between the multiplexer and the emitter, and having a semiconductor optical amplifier (SOA) structure.

An optical apparatus may include the beam steering device, a light receiver configured to receive light that is emitted from the beam steering device and reflected from an object, and a circuit connected to either one or both of the beam steering device and the light receiver.

The optical apparatus may further include a demultiplexer disposed between the object and the light receiver, and configured to demultiplex the reflected light, and divide the demultiplexed light into reflected lights having third different wavelengths, the light receiver may be further configured to receive the reflected lights.

The light receiver may include photo detecting elements, and the optical apparatus may be configured to acquire information of the third different wavelengths of the reflected lights, using the photo detecting elements, and analyze information of the object, based on the acquired information.

The optical apparatus may be a LiDAR apparatus.

According to an aspect of another example embodiment, there is provided a beam steering device including an input coupler configured to simultaneously receive input lights having first different wavelengths, and an output coupler configured to simultaneously emit output lights having second different wavelengths to different points arranged in a first direction, and move the emitted output lights in a second direction different from the first direction, based on the received input lights.

The beam steering device may further include waveguides disposed between the input coupler and the output coupler, the first direction may be parallel to an extension direction of the waveguides, and the second direction may be perpendicular to the extension direction of the waveguides.

The beam steering device may further include an optical modulator disposed between the input coupler and the output coupler, and configured to move the emitted output lights in the second direction, based on the received input lights.

The received input lights may include lasers having the first different wavelengths.

The input coupler may include a multiplexer configured to simultaneously receive the input lights, and multiplex the received input lights.

An optical apparatus may include the beam steering device, a light receiver configured to receive light that is emitted from the beam steering device and reflected from an object; and a circuit connected to either one or both of the beam steering device and the light receiver.

The optical apparatus may further include a demultiplexer disposed between the object and the light receiver, and configured to demultiplex the reflected light, and divide the demultiplexed light into reflected lights having third different wavelengths, and the light receiver may be further configured to receive the reflected lights.

According to an aspect of an example embodiment, there is provided a beam steering device including a multiplexer configured to simultaneously receive input lights having first different wavelengths, and multiplex the received input lights into a multiplexed light, and an optical splitter configured to split the multiplexed light. The beam steering apparatus further includes an optical modulator configured to modulate the split light, and an emitter configured to simultaneously emit output lights having second different wavelengths to different points arranged in a first direction and of an object, and move the emitted output lights in a second direction different from the first direction, based on the modulated light.

The beam steering device may further include laser sources configured to generate lasers having the first different wavelengths, and input couplers configured to simultaneously receive the generated lasers, and transmit the received lasers to the multiplexer as the input lights.

Either one or both of the emitter and the optical modulator may include a substrate, an insulative layer disposed on the substrate, and waveguides disposed on the insulative layer. The first direction may be parallel to an extension direction of the waveguides, and the second direction may be perpendicular to the extension direction of the waveguides.

The beam steering device may further include a cover layer disposed on the multiplexer, the optical splitter, the optical modulator, and the emitter.

An optical apparatus may include the beam steering device, and a demultiplexer configured to receive light that is reflected from the object, demultiplex the reflected light, and divide the demultiplexed light into reflected lights having third different wavelengths. The optical apparatus may further include a filter configured to filter the reflected lights, and a light receiver configured to receive the filtered reflected lights.

The above and/or other aspects will become apparent and more readily appreciated from the following description of example embodiments, taken in conjunction with the accompanying drawings in which:.

Also, well-known functions or constructions may not be described in detail because they would obscure the description with unnecessary detail.

As used herein the term "and/or" includes any and all combinations of one or more of the associated listed items.

It will be understood that, although the terms "first," "second," etc. may be used herein to describe various elements, components, regions, layers and/or sections, these elements, components, regions, layers and/or sections may not be limited by these terms. Thus, a first element, component, region, layer or section discussed below could be termed a second element, component, region, layer or section without departing from the teachings of example embodiments.

Thus, the term "below" can encompass both an orientation of above and below.

The terminology used herein is for the purpose of describing example embodiments only and is not intended to be limiting of example embodiments.

Example embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations of idealized embodiments (and intermediate structures) of example embodiments. Thus, example embodiments may not be construed as limited to the shapes of regions illustrated herein but are to include deviations in shapes that result, for example, from manufacturing. For example, an implanted region illustrated as a rectangle will have rounded or curved features and/or a gradient of implant concentration at its edges rather than a binary change from implanted to non-implanted region. Likewise, a buried region formed by implantation may result in some implantation in the region between the buried region and the surface through which the implantation takes place. Thus, the regions illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the actual shape of a region of a device and are not intended to limit the scope of example embodiments. Unless otherwise defined, all terms including technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skilled.

in the art to which example embodiments belong. It will be further understood that terms, such as those defined in commonly-used dictionaries, may be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

Hereinafter, beam steering devices and optical apparatuses including the beam steering devices will be described according to example embodiments with reference to the accompanying drawings. In the drawings, the widths and thicknesses of layers or regions may be exaggerated for clarity or ease of description.

<FIG> and <FIG> are schematic views illustrating a beam steering device D100 according to an example embodiment.

Referring to <FIG>, the beam steering device D100 may include an input coupler IN10 and an output coupler OUT10. A plurality of lights (beams) L10 having different wavelengths may be simultaneously input through the input coupler IN10. In other words, multi-wavelength (multi-λ) light L10 may be input through the input coupler IN10.

A plurality of output lights (beams) L20 having different wavelengths may be simultaneously emitted toward an object OBJ through the output coupler OUT10. The plurality of output lights L20 are simultaneously emitted to different points arranged in a first direction DD1. The points toward which the output lights L20 are emitted may be one-dimensionally arranged. In other words, the output lights L20 may be simultaneously emitted toward a plurality of points that are one-dimensionally arranged in a line. The wavelengths of the output lights L20 may include a first wavelength λ<NUM>, a second wavelength λ<NUM>, a third wavelength λ<NUM>, a fourth wavelength λ<NUM>, etc. However, this is an example. That is, the number of the wavelengths of the output lights L20 may vary.

The illustrated structure of the object OBJ is an example. That is, the object OBJ may have a different structure, size, etc. The object OBJ is not limited to a type. For example, the object OBJ may be a space or anything existing in a space.

According to the example embodiment, the beam steering device D100 simultaneously emits the plurality of output lights L20 having different wavelengths to detect/search a plurality of points in the first direction DD1. In addition, the beam steering device D100 varies (changes) the emission directions of the output lights L20 in a direction different from the first direction DD1. This will now be described with reference to <FIG>.

Referring to <FIG>, the beam steering device D100 is configured to change the emission directions of the output lights L20 in a second direction DD2 different from the first direction DD1. The second direction DD2 is perpendicular to the first direction DD1. The emission directions of the output lights L20 are varied in the second direction DD2 by optical modulation performed in the beam steering device D100. The emission directions of the output lights L20 having different wavelengths (for example, wavelengths λ<NUM> to λ<NUM>) may vary with time in the second direction DD2 as a result of the optical modulation. Thus, the second direction DD2 may be referred to as a "scanning direction.

According to the example embodiment, the beam steering device D100 may perform a scanning operation while changing the emission directions of the output lights L20 in the second direction DD2. Therefore, the beam steering device D100 may perform a two-dimensional scanning operation at a relatively high speed compared to point-by-point beam steering devices.

<FIG> is a schematic view illustrating a beam steering device D10 according to a comparative example.

Referring to <FIG>, the beam steering device D10 of the comparative example may perform a point-by-point scanning operation. For example, the beam steering device D10 of the comparative example may scan an object OBJ while moving an output light (beam) having a single wavelength λ<NUM> in a scanning direction. The output light having a single wavelength λ<NUM> may be emitted to a first point at a first time point T1, a second point at a second time point T2, a third point at a third time point T3, a fourth point at a fourth time point T4, and a fifth point at a fifth time point T5. Thus, it may be considered that the beam steering device D10 performs a one-dimensional scanning operation. Complex and difficult techniques may be used to perform a two-dimensional scanning operation, using the beam steering device D10. In addition, because such a one-dimensional or two-dimensional scanning operation is performed basically by using a point-by-point method, the speed, accuracy, and precision of the scanning operation may be low. For example, because the first point is detected at the first time point T1 and the fifth point is detected at the fifth time point T5, the accuracy and precision of detection may be low because of a detection time difference. The accuracy and precision of detection/analysis may be decreased as the speed of scanning is decreased.

However, if the beam steering device D100 of the example embodiment is used, a two-dimensional scanning operation may be performed at a high speed by simultaneously emitting the plurality of output lights L20 having different wavelengths. Thus, the speed of detection/analysis may be increased, and the accuracy and precision of detection/analysis may be markedly improved.

<FIG> is a block diagram illustrating an example configuration of the beam steering device D100 depicted in <FIG>. In <FIG>, the beam steering device D100 is indicated using a reference numeral <NUM>.

Referring to <FIG>, a light source unit <NUM> generates a plurality of lights L11 having different wavelengths. The plurality of lights L11 are referred to as multi-wavelength (multi-λ) electromagnetic waves. For example, the plurality of lights L11 are a plurality of lasers (laser beams) having different wavelengths. However, the plurality of lights L11 may be another kind of light other than a laser. The light source unit <NUM> generates the plurality of lights L11 at the same time.

A multiplexer (MUX) <NUM> simultaneously receives and multiplexes the plurality of lights L11 generated by the light source unit <NUM>. The multiplexer <NUM> has a general optical multiplexer structure. In addition, the multiplexer <NUM> also functions as an input coupler.

An optical splitter <NUM> splits the light multiplexed by the multiplexer <NUM>. The optical splitter <NUM> is a beam splitter. Each of lights (beams) split by the optical splitter <NUM> has multiple wavelengths (multi-λ).

An optical modulator <NUM> modulates the multiplexed light split by the optical splitter <NUM>. The optical modulator <NUM> may modulate light by various methods. For example, the optical modulator <NUM> can modulate the phase of the light split by the optical splitter <NUM>. Alternatively, the optical modulator <NUM> can modulate the amplitude of the light split by the optical splitter <NUM>. Alternatively, the optical modulator <NUM> can modulate both the phase and amplitude of the light split by the optical splitter <NUM>. In addition to this, the optical modulator <NUM> may have other optical modulation functions. The optical modulator <NUM> performs optical modulation by using a method such as an electric method, a magnetic method, a thermal method, or a mechanical method. For example, the optical modulator <NUM> includes at least one phase shifter (or phase shifting element), and the phase shifter includes at least one selected from the group consisting of a gain element, an all-pass filter, a Bragg grating, a dispersive material element, a wavelength tuning element, and a phase tuning element. In addition, an actuation mechanism of the optical modulator <NUM> includes at least one selected from the group consisting of a thermo-optic actuation mechanism, an electro-optic actuation mechanism, an electroabsorption actuation mechanism, a free carrier absorption actuation mechanism, a magneto-optic actuation mechanism, a liquid crystal actuation mechanism, and an all-optical actuation mechanism. The actuation mechanism of the optical modulator <NUM> is related to the above-described phase tuning. The phase shifter and the actuation mechanism of the optical modulator <NUM> of the example embodiment are not limited to the above examples.

An emitting portion (emitter) <NUM> receives light from the optical modulator <NUM> and simultaneously emits a plurality of output lights L22. The output lights L22 have different wavelengths (for example, wavelengths λ<NUM>, λ<NUM>, λ<NUM>,. The plurality of output lights L22 are emitted to different points arranged in a first direction DD1. The wavelengths of the output lights L22 correspond to or be similar to the wavelengths of the lights L11 generated by the light source unit <NUM>. The output lights L22 correspond to the output lights L20 described with reference to <FIG>.

Due to the optical modulation by the optical modulator <NUM>, the emission directions of the output lights L22 are varied in a second direction DD2 different from the first direction DD1. For example, as the optical modulator <NUM> performs a modulation operation such as a phase modulation operation on light (split lights), the emission directions of the output lights L22 are varied in the second direction DD2. FoThe second direction DD2 is perpendicular to the first direction DD1. The first direction DD1 and the second direction DD2 correspond to the first direction DD1 and the second direction DD2 described with reference to <FIG>. Thus, the second direction DD2 may be referred to as a scanning direction.

The emitter <NUM> is an output coupler. For example, the emitter <NUM> includes a plurality of waveguides. In addition, the emitter <NUM> further includes grating structures formed on the waveguides. The grating structures are designed to direct a beam having a wavelength in a direction. However, the configuration of the emitter <NUM> is not limited thereto. That is, the configuration of the emitter <NUM> may be variously modified.

In the example embodiment, the beam steering device <NUM> includes the multiplexer <NUM>, the optical splitter <NUM>, the optical modulator <NUM>, and the emitter <NUM>. In this case, the multiplexer <NUM> is an input coupler, and the emitter <NUM> is an output coupler. The multiplexer <NUM>, the optical splitter <NUM>, the optical modulator <NUM>, and the emitter <NUM> form a single device (an optical semiconductor device), and the light source unit <NUM> is provided separately from the single device and emits a plurality of lights L11 toward the multiplexer <NUM>. In a broad sense, however, the light source unit <NUM> is considered as a part of the beam steering device <NUM>. That is, it is considered that the beam steering device <NUM> includes the light source unit <NUM>, the multiplexer <NUM>, the optical splitter <NUM>, the optical modulator <NUM>, and the emitter <NUM>. That is, the multiplexer <NUM>, the optical splitter <NUM>, the optical modulator <NUM>, and the emitter <NUM> may be provided on a single chip, or the light source unit <NUM>, the multiplexer.

<NUM>, the optical splitter <NUM>, the optical modulator <NUM>, and the emitter <NUM> may be provided on a single chip.

Hereinafter, the configurations of light source units and input units (input couplers) applicable to beam steering devices will be described with reference to <FIG>.

<FIG> is a block diagram illustrating a light source unit and an input unit applicable to a beam steering device according to an example embodiment.

Referring to <FIG>, in the example embodiment, a light source unit <NUM> may include a plurality of laser sources LD1 to LD4. Although four laser sources LD1 to LD4 are illustrated, the number of the laser sources may vary. The laser sources LD1 to LD4 may be laser diodes. The laser sources LD1 to LD4 may generate a plurality of lasers (laser beams) having different wavelengths (for example, wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM>). The plurality of lasers having different wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM> that are generated by the laser sources LD1 to LD4 may be input to a multiplexer <NUM> and may be multiplexed. In this case, the multiplexer <NUM> may be considered as an input coupler (input unit). The light multiplexed by the multiplexer <NUM> may be split by an optical splitter <NUM>. A configuration after the optical splitter <NUM> may be substantially the same as or similar to that described with reference to <FIG>. According to another example embodiment, a multimode laser source may be used instead of the plurality of laser sources LD1 to LD4. In this case, the multimode laser source may generate a plurality of lasers (laser beams) having different wavelengths.

<FIG> is a block diagram illustrating a light source unit and an input unit applicable to a beam steering device according to another example embodiment.

Referring to <FIG>, lasers having different wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM> that are generated by laser sources LD1 to LD4 may be input to different input couplers IN1 to IN4, respectively. The input couplers IN1 to IN4 may constitute an "input unit <NUM>. " For example, the input couplers IN1 to IN4 may have an optical fiber structure or another structure. After passing through the input couplers IN1 to IN4, the plurality of lights may be multiplexed by a multiplexer <NUM> and may then be split by an optical splitter <NUM>. A configuration after the optical splitter <NUM> may be substantially the same as or similar to that described with reference to <FIG>.

The input couplers IN1 to IN4 and the multiplexer <NUM> illustrated in <FIG> may be connected to each other by an optical waveguide. In some cases, the combination of the input couplers IN1 to IN4 and the multiplexer <NUM> may be considered as an "input unit.

Referring to <FIG>, a light source unit <NUM> may include a laser source LD10 configured to generate a laser having a single wavelength λ<NUM>. That is, the light source unit <NUM> may be constituted by a single laser source LD10. A wavelength converter <NUM> may divide the laser generated by the laser source LD10 into a plurality of lasers having different wavelengths (for example, wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM>). For example, the wavelength converter <NUM> may include an input coupler, an optical divider, and a plurality of wavelength converting elements. A laser input to the input coupler may be divided by the optical divider, and the wavelength of the divided laser may be converted by the wavelength converting elements. As a result, a plurality of lights having different wavelengths (for example, wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM>) may be output from the wavelength converter <NUM>. Then, the lights may be multiplexed by a multiplexer <NUM> and may then be split by an optical splitter <NUM>. A configuration after the optical splitter <NUM> may be equal or similar to that described with reference to <FIG>. The above-described configuration of the wavelength converter <NUM> is an example. That is, the configuration of the wavelength converter <NUM> may be variously modified.

The combination of the laser source LD10 and the wavelength converter <NUM> illustrated in <FIG> may be considered as a "light source unit. " That is, it may be considered that such a light source unit generates a plurality of lights having different wavelengths (for example, wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM>). In addition, at least a portion of the wavelength converter <NUM> or at least a portion of the multiplexer <NUM> may be considered as an "input coupler. " Alternatively, the combination of the wavelength converter <NUM> and the multiplexer <NUM> may be considered as an input coupler.

Referring to <FIG>, a light source unit <NUM> may include a light emitting diode (LED). For example, the LED may be a white LED. In other words, the LED may be a device capable of emitting a wideband light. A multi-band pass filter <NUM> may divide the light generated by the light source unit <NUM>. A plurality of lights having a plurality of wavelengths (for example, wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM>) may be output through the multi-band pass filter <NUM>. Then, the plurality of lights may be multiplexed by a multiplexer <NUM> and may then be split by an optical splitter <NUM>. A configuration after the optical splitter <NUM> may be equal or similar to that described with reference to <FIG>.

The combination of the LED (that is, the light source unit <NUM>) and the multi-band pass filter <NUM> illustrated in <FIG> may be considered as a "light source unit. " It may be considered that such a light source unit generates a plurality of lights having different wavelengths. In the example embodiment, the multiplexer <NUM> may be considered as an "input coupler.

<FIG> is a plan view illustrating light split by an optical splitter 300A applicable to a beam steering device according to an example embodiment.

Referring to <FIG>, a light multiplexed by a multiplexer (such as the multiplexer <NUM> illustrated in <FIG>) is input to the optical splitter 300A and is split by the optical splitter 300A. The split lights may be output (may propagate) through a plurality of optical path elements W10. The optical path elements W10 are waveguides. For example, the optical path elements W10 may include first to eighth optical path elements w11 to w18. The first to eighth optical path elements w11 to w18 are examples. That is, the number of the optical path elements W10 may vary. Light output (propagating) through each of the first to eighth optical path elements w11 to w18 may have multiple wavelengths. The light output (propagating) through each of the first to eighth optical path elements w11 to w18 may include lights having wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM> illustrated in <FIG>, for example. The optical splitter 300A may have a multimode interference (MMI) structure or another structure. In addition, the optical splitter 300A may use a multi-step beam splitting structure to increase the number of split beams. The structure of the optical splitter 300A may be variously modified.

<FIG> is a plan view illustrating light modulation by an optical modulator 400A applicable to a beam steering device according to an example embodiment.

Referring to <FIG>, the optical modulator 400A may be placed on a plurality of optical path elements W10. The optical modulator 400A may be placed above or below the optical path elements W10. It may be considered that the optical path elements W10 are included in the optical modulator 400A. The optical path elements W10 may be those extending from the optical path elements W10 described with reference to <FIG>. For example, the optical path elements W10 may include first to eighth optical path elements w11 to w18. However, the number of the optical path elements W10 is not limited thereto. The optical modulator 400A may modulate lights propagating through the optical path elements W10. The optical modulator 400A may modulate lights propagating through the first to eighth optical path elements w11 to w18. For example, a light propagating through the first optical path element w11 may be modulated to a first degree, a light propagating through the second optical path element w12 may be modulated to a second degree, a light propagating through the third optical path element w13 may be modulated to a third degree, a light propagating through the fourth optical path element w14 may be modulated to a fourth degree, a light propagating through the fifth optical path element w15 may be modulated to a fifth degree, a light propagating through the sixth optical path element w16 may be modulated to a sixth degree, a light propagating through the seventh optical path element w17 may be modulated to a seventh degree, and a light propagating through the eighth optical path element w18 may be modulated to an eighth degree. In other words, lights propagating through the first to eighth optical path elements w11 to w18 may be modulated to different degrees. As a result, the wavefronts of lights output from the first to eighth optical path elements w11 to w18 may be adjusted to control the directions of the output lights (beams). For example, the emission direction of the output light is varied in a direction such as a second direction DD2 owing to optical modulation performed by the optical modulator 400A.

The structure and operational mechanism of the optical modulator 400A may be variously modified. For example, the optical modulator 400A may be configured to perform phase modulation, amplitude modulation, or phase-amplitude modulation. In addition, the optical modulator 400A may perform optical modulation by using a method such as an electric method, a magnetic method, a thermal method, or a mechanical method. In addition, for example, the structure, size, and number of the optical path elements W10 illustrated in <FIG> may be variously modified.

<FIG> is a perspective view illustrating a relationship between a steering direction and waveguides applicable to a beam steering device according to an example embodiment.

Referring to <FIG>, the beam steering device may include a plurality of waveguides W1 formed on a substrate SUB1. An insulative layer N1 may be provided on the substrate SUB1, and the waveguides W1 may be arranged on the insulative layer N1. The insulative layer N1 is optional. That is, the insulative layer N1 may not be included in example embodiments. The waveguides W1 may extend in a direction. The waveguides W1 may be arranged in parallel with each other.

The plurality of waveguides W1 are included in the output coupler OUT10 or the emitter <NUM> illustrated with reference to <FIG> or <FIG>. In other words, the output coupler OUT10 and the emitter <NUM> include the plurality of waveguides W1. Each of the waveguides W1 comprises a grating structure. The characteristics or directions of lights (beams) output from the waveguides W1 varies according to the shapes, sizes, or pattern intervals of the grating structures of the waveguides W1. Thus, the waveguides W1 may be considered as a grating coupler. In example embodiments, the optical modulator <NUM> illustrated in <FIG> may include the plurality of waveguides W1. In this case, the optical modulator <NUM> may modulate lights propagating through the plurality of waveguides W1.

For example, the first direction DD1 described with reference to <FIG> and <FIG> is parallel to an extension direction of the waveguides W1 illustrated in <FIG>, and the second direction DD2 is perpendicular to the extension direction of the waveguides W1 illustrated in <FIG>. In other words, a plurality of output lights (refer to the output lights L20 illustrated in <FIG>) spread in a direction parallel to the extension direction of the waveguides W1, and as a result of the optical modulation, the emission directions of the output lights (refer to the output lights L20 illustrated in <FIG>) vary in a direction perpendicular to the extension direction of the waveguides W1.

The structure and extension direction of the waveguides W1 illustrated in <FIG> are examples. That is, the structure and extension direction of the waveguides W1 may be variously modified. In addition, the relationship between the extension direction of the waveguides W1 and a steering direction is not limited to the description presented above.

<FIG> is a cross-sectional view schematically illustrating a beam steering device provided in the form of a single device (semiconductor device), according to an example embodiment.

Referring to <FIG>, the beam steering device may include an input coupler E10 and an output coupler E40 that are arranged on a substrate SUB10. In addition, the beam steering device may further include an optical splitter E20 and an optical modulator E30 that are arranged between the input coupler E10 and the output coupler E40. An insulative layer N10 may be optionally provided on the substrate SUB10, and the input coupler E10, the optical splitter E20, the optical modulator E30, and the output coupler E40 may be arranged on the insulative layer N10. Optical waveguide(s) may be provided between two neighboring elements, that is, between the input coupler E10 and the optical splitter E20, between the optical splitter E20 and the optical modulator E30, and between the optical modulator E30 and the output coupler E40.

The input coupler E10 may be configured to receive a plurality of lights having different wavelengths. To this end, the input coupler E10 may include a multiplexer. For example, the optical splitter E20 may have a multimode interference (MMI) structure or another structure. The optical modulator E30 may perform an optical modulation operation by using an electric method or another method such as a magnetic method, a thermal method, or a mechanical method. In addition, the optical modulator E30 may use various modulation methods such as a phase modulation method or an amplitude modulation method. The optical modulator E30 may include a plurality of waveguides and may modulate beams propagating through the waveguides. For example, the output coupler E40 may include a plurality of waveguides and grating structures respectively formed on the waveguides. The structures of the input coupler E10, the optical splitter E20, the optical modulator and the output coupler E40 are not limited to those described above and may be variously modified.

A cover layer C10 may be further provided on the substrate SUB10 to cover the input coupler E10, the optical splitter E20, the optical modulator E30, and the output coupler E40. The cover layer C10 may include a low refractive material having a relatively low refractive index. For example, the cover layer C10 may include a dielectric material such as a silicon oxide or a polymer-based material. The cover layer C10 may also function as a protective layer. However, the cover layer C10 may not be provided in example embodiments.

Any one or any combination of the input coupler E10, the optical splitter E20, the optical modulator E30, and the output coupler E40 may include: any one or any combination of a group IV element such as silicon (Si) or germanium (Ge); a compound containing a group IV element such as SiGe; a group III-V compound; an oxide; a nitride; and a polymer. In example embodiments, at least two of the input coupler E10, the optical splitter E20, the optical modulator E30, and the output coupler E40 may include different materials. If the substrate SUB10 includes silicon (Si), or any one or any combination of the input coupler E10, the optical splitter E20, the optical modulator E30, and the output coupler E40 includes silicon (Si), the beam steering device of the example embodiment may be implemented/manufactured using a silicon photonics technique. Because the silicon photonics technique is used in (that is, compatible with) a complementary metal oxide semiconductor (CMOS) process, the silicon photonics technique may make it easy to perform manufacturing processes.

<FIG> is a block diagram illustrating an example configuration of a beam steering device <NUM> according to another example embodiment. The beam steering device <NUM> of the current example embodiment is a modification of the beam steering device <NUM> illustrated in <FIG>.

Referring to <FIG>, the beam steering device <NUM> may further include an amplifier <NUM> between a multiplexer <NUM> and an emitter <NUM>. For example, the amplifier <NUM> may be placed between an optical modulator <NUM> and the emitter <NUM>. The amplifier <NUM> may have a semiconductor optical amplifier (SOA) structure, for example. The amplifier <NUM> may amplify optical signals so that the intensity of lights generated by a light source unit <NUM> may be maintained at the emitter <NUM>. Alternatively, the amplifier <NUM> may increase a signal-to-noise ratio (SNR). The position and configuration of the amplifier <NUM> described with reference to <FIG> are examples. That is, the position and configuration of the amplifier <NUM> may vary.

<FIG> is a graph illustrating a light type as an example of light applicable to a beam steering device according to an example embodiment.

Referring to <FIG>, the light generated by a light source unit of the beam steering device may have a pulse waveform. For example, if the light source unit generates a laser, the laser may be a pulsed laser. Thus, ON and OFF states of the light may be alternately repeated, and in the ON state, light having a wavelength (or wavelength band) may be generated as shown in an enlarged section on the right side of <FIG>. For example, the wavelength of the light may correspond to one of wavelengths λ<NUM>, λ<NUM>, λ<NUM>, and λ<NUM> shown in <FIG>. A pulse wave (for example, a pulsed laser) is different from a continuous wave (CW) or a CW laser. The CW laser may be used for the Doppler effect, and the pulse wave (for example, pulsed laser) may be used for other purposes and effects. However, the type of light used according to example embodiments is not limited to the type described with reference to <FIG>. That is, the type of light may vary according to example embodiments.

The above-described beam steering devices of the example embodiments may be applied to various optical apparatuses. For example, the beam steering devices may be applied to light detection and ranging (LiDAR) apparatuses.

<FIG> is a diagram illustrating an optical apparatus including a beam steering device <NUM> according to an example embodiment. The optical apparatus of the example embodiment may be a LiDAR apparatus.

Referring to <FIG>, the beam steering device <NUM> of the optical apparatus may correspond to one of the beam steering devices D100, <NUM>, and <NUM> of the previous example embodiments, or may be obtained by modifying the beam steering devices D100, <NUM>, and <NUM>. In the current example embodiment, the beam steering device <NUM> may have the configuration illustrated in <FIG>. That is, the beam steering device <NUM> may include a light source unit <NUM>, a multiplexer <NUM>, an optical splitter <NUM>, an optical modulator <NUM>, and an emitter <NUM>. The beam steering device <NUM> may simultaneously emit a plurality of output lights L22 having different wavelengths toward an object OBJ. The output lights L22 may be emitted to different points arranged in a first direction DD1, simultaneously. The emission directions of the output lights L22 may be varied in a second direction DD2 different from the first direction DD1. The second direction DD2 may be perpendicular to the first direction DD1. The second direction DD2 may be referred to as a scanning direction.

The optical apparatus may include a light receiver <NUM> to receive the output lights L22 emitted from the beam steering device <NUM> and reflected from the object OBJ, that is, to receive reflected light. Reflection may include general reflection and scattering. In addition, "reflection" may include variations (modulations) of light caused by the object OBJ. The light receiver <NUM> may include a plurality of photo detecting elements, and the photo detecting elements may have an arrayed structure. For example, the photo detecting elements may include photodiodes, phototransistors, and/or charge-coupled devices (CCDs).

The optical apparatus may further include a demultiplexer (DEMUX) <NUM> between the object OBJ and the light receiver <NUM>. The demultiplexer <NUM> may demultiplex light reflected from the object OBJ to divide the light into a plurality of lights having different wavelengths (for example, λ<NUM>, λ<NUM>, λ<NUM>,. The wavelengths (for example, λ<NUM>, λ<NUM>, λ<NUM>,. , and λn) may respectively correspond to or may be respectively similar to the wavelengths (for example, λ<NUM>, λ<NUM>, λ<NUM>,. , and λn) of the output lights L22 emitted from the beam steering device <NUM>.

In addition, the optical apparatus may further include a circuit unit <NUM> connected to either one or both of the beam steering device <NUM> and the light receiver <NUM>. The circuit unit <NUM> may include a calculating portion configured to acquire data and perform computation using the data. The circuit unit <NUM> may further include a driver or a controller. In addition, the circuit unit <NUM> may further include a power source unit and a memory. The configuration of the circuit unit <NUM> may be variously modified according to the type of the optical apparatus. The circuit unit <NUM> may be connected to a user interface UI.

The optical apparatus of the example embodiment may use the light receiver <NUM> to acquire information about a plurality of wavelengths from light reflected from the object OBJ and analyze information about the object OBJ, based on the acquired information. If the light receiver <NUM> includes a plurality of photo detecting elements, the photo detecting elements may be used to obtain information about a plurality of wavelengths and analyze information about the object OBJ, based on the acquired information. Three-dimensional information about the object OBJ may be rapidly and precisely obtained by rapidly scanning the object OBJ in a two-dimensional manner, using a plurality of output lights L22 having different wavelengths.

In example embodiments, the optical apparatus illustrated in <FIG> may further include at least one optical element. For example, the optical apparatus may further include a filter to detect light reflection points, according to wavelengths, and/or another optical element to control the intensity of light, according to wavelengths between the object OBJ and the light receiver <NUM>. An example of this is illustrated in <FIG>.

<FIG> is a diagram illustrating an optical apparatus including a beam steering device <NUM> according to another example embodiment.

Referring to <FIG>, a filter <NUM> may be provided between the demultiplexer <NUM> and the light receiver <NUM>. Light may be divided into multiple wavelengths by the demultiplexer <NUM>, and light of a wavelength may reach a pixel of the light receiver <NUM> through the filter <NUM>. Thus, the filter <NUM> may be used to determine the position at which light of a wavelength is reflected from the object OBJ. At least one other optical element may be used instead of or together with the filter <NUM> between the demultiplexer <NUM> and the light receiver <NUM>. For example, the at least one other optical element may include an optical element configured to control the intensity of reflected light according to the wavelengths of the reflected light. The intensity of reflected light may be controlled according to the wavelengths of the reflected light by using such an optical element. In addition, the optical apparatus of the example embodiment may further include a resonator or another optical element.

<FIG> is a block diagram illustrating an overall systematic structure of an optical apparatus A1 including a beam steering device 1000A according to an example embodiment.

Referring to <FIG>, the optical apparatus A1 may include the beam steering device 1000A. The beam steering device 1000A may correspond to or may be similar to the beam steering devices described with reference to <FIG>, <FIG>, and <FIG> to <NUM>. The optical apparatus A1 may include a light source unit provided as a part of or independently of the beam steering device 1000A.

The optical apparatus A1 may include a detector 2000A to detect light steered by the beam steering device 1000A and reflected from an object. The detector 2000A may include the light receiver <NUM> described with reference to <FIG>. In addition, the detector 2000A may further include the demultiplexer <NUM> described with reference to <FIG>. In addition, the detector 2000A may further include the filter <NUM> described with reference to <FIG> or another optical element.

In addition, the optical apparatus A1 may further include a circuit unit 3000A connected to either one or both of the beam steering device 1000A and the detector 2000A. The circuit unit 3000A may include a calculating portion configured to acquire data and perform computation using the data. The circuit unit 3000A may further include a driver or a controller. In addition, the circuit unit 3000A may further include a power source unit and a memory.

<FIG> illustrates that the optical apparatus A1 includes the beam steering device 1000A and the detector 2000A in a single device or apparatus. However, the beam steering device 1000A and the detector 2000A may be provided separately from each other in independent devices. In addition, the circuit 3000A may be connected to the beam steering device 1000A or the detector 2000A by a wireless communication method instead of a wired communication method. The configuration illustrated in <FIG> may be variously modified.

The optical apparatuses of the example embodiments may be LiDAR apparatuses. The LiDAR apparatuses may be time-of-flight (TOF) or phase-shift type apparatuses. The LiDAR apparatuses may be applied to autonomous vehicles, aircrafts such as drones, mobile devices, small vehicles (such as bicycles, motorcycles, babe carriages, or boards), robots, assistant devices or items for humans/animals (such as sticks, helmets, accessories, clothes, watches, or bags), Internet of Things (IoT) devices/systems, security devices/systems, etc. Because the beam steering devices and the optical apparatuses including the beam steering devices according to the example embodiments are usable to obtain three-dimensional information about spaces and objects via two-dimensional scanning, the beam steering devices and the optical apparatuses may be applied to three-dimensional image acquisition apparatuses or three-dimensional cameras. In addition, the beam steering devices and the optical apparatuses including the beam steering devices according to the example embodiments may be used for various purposes in a wide range of optical fields and electronic fields.

Claim 1:
A beam steering device comprising:
a multiplexer (<NUM>) configured to simultaneously receive input lights (<NUM>) having first different wavelengths, and multiplex the received input lights into a multiplexed light;
an optical splitter (<NUM>) configured to split the multiplexed light, each of the split light having multiple wavelengths;
an optical modulator (<NUM>) configured to modulate the split light; and
an emitter (<NUM>) comprising a plurality of waveguides extending in a first direction, the waveguides further comprising a grating structure, the waveguides configured to simultaneously emit output lights having second different wavelengths to different points arranged in the first direction, based on the modulated light, wherein the characteristics or direction of emitting output light from each waveguide varies according to the grating structure;
and characterized in that the optical modulator (<NUM>) is adapted to modulate at least one of the phase and amplitude of the split light to different degrees to adjust the wavefronts of the emitter lights output from the emitter to vary the directions of the emitted output lights in a second direction perpendicular to the first direction.