Near-field recording head capable of directly forming light source in slider

A near-field optical head capable of being significantly miniaturized is constituted by a near-field optical probe slider formed by holding, on a slider, a semiconductor laser, a heat dissipation member, a prism for guiding light from the semiconductor laser to a scattering body and a photodetector element.

BACKGROUND OF THE INVENTION

I. Technical Field

The present invention relates to a near-field optical head, and a near-field optical head device, a near-field optical information device and a near-field optical information system provided with the same, and relates to a device capable of recording or reproducing information at a higher density in or from a medium.

II. Description of the Related Art

In the field of optical information recording, notice has been taken of optical recording using a near field light. The prior art described in Japanese Patent Laid-Open Publication No. 2004-151046 presents a method for making a higher-density record with a near field light.FIGS. 13 to 15show the configuration and main part of a near-field optical head device according to the prior art.

InFIGS. 13 and 14, a near-field optical probe slider702facing a disk701as a recording medium is provided with beam-condensing elements integrated therein and receives a parallel beam from an optical head703. A carriage actuator704moves the optical head703in radial directions of the disk701. A beam emitted from a semiconductor laser708as a light source passes through a collimating lens709and a beam-shaping prism710to become a circular parallel beam in the optical head703and is incident upon the near-field optical probe slider702through a beam splitter712and a mirror714. The near-field optical probe slider702is subjected to an adjustment of the position thereof in the tracking directions by a piezo-electric element711and pressed onto the disk701by the force of a suspension705attached thereto.

FIG. 15is a schematic side view of the near-field optical probe slider702provided with a scattering body21facing a disk27as a recording medium and a substrate24supporting this. The scattering body21and the substrate24are arranged on the near-field optical probe slider702in such a way that the distance between the scattering body21and the disk27is kept below tens nanometers. Light radiated from a light source19is incident upon the scattering body21through a collimating lens18and a beam-condensing element17to thereby generate intense near field light at the part of the scattering body21proximate to the disk27. If the disk27is provided with a phase-change material, the near field light generated from the scattering body21changes the crystal phase into an amorphous phase to thereby form a record mark.

On the other hand, the reproduction is conducted, as shown inFIGS. 13 and 14, by detecting a variation in the intensity of light returning from the disk701, more specifically, because the percentage of the near field light scattered by the disk701varies according to the presence of the record mark, by detecting a variation in the intensity of the scattered light. In practice, the light (signal light) from the disk701is split from the incident light by the beam splitter712and detected by a detector717after passing through a condensing lens715. In the prior art, the polarization direction of the signal light from the disk701differs from the polarization direction of the incident light, thereby improving the contrast by setting the polarization direction of a polarizer716on the optical path perpendicular to the incident-light polarization direction.

However, in the near-field optical head device according to the prior art, the near-field optical probe slider702provided with the scattering body21generating a near field and the optical head703provided with a light source exist individually, thereby hindering miniaturizing the near-field optical head.

Specifically, in order to keep the distance between the scattering body21and the disk27shorter than several tens nanometers, the near-field optical probe slider702needs to be smaller and to be provided only with the scattering body21and the substrate24thereon, thereby meaning that the near-field optical probe slider702and the optical head703have to be separately formed by an individual member. Besides, in order to send a beam emitted from the semiconductor laser708as a light source to irradiate the whole main surface of the scattering body21parallel to the disk701, the emitted beam from the semiconductor laser708needs to be incident from behind the scattering body21, thereby requiring many optical devices such as the collimating lens709, the beam-shaping prism710, the beam splitter712and the mirror714. This makes the optical head703and the whole near-field optical head larger.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a near-field optical head capable of recording or reproducing information at a higher density in or from a medium and being significantly miniaturized, and a near-field optical head device, a near-field optical information device and a near-field optical information system of small size provided with the near-field optical head.

A near-field optical head according to an aspect of the present invention includes: a light source; a scattering member having a substantially flat-plane shape; and a slider holding the light source and the scattering member, in which: the slider holds the scattering member in such a way that an end of the scattering member is proximate to a medium; the scattering member has a first plane located on the side of the light source and substantially perpendicular to the medium; light emitted from the light source irradiates the first plane substantially perpendicularly; and the end of the scattering member generates near field light and applies the near field light to the medium.

The near-field optical head can apply light emitted from the light source substantially perpendicularly to the first plane of the scattering member substantially perpendicular to the medium to thereby generate near field light from the end of the scattering member and apply it to the medium. This makes it possible to simplify the configuration of a recording optical system and significantly miniaturize the near-field optical head capable of recording or reproducing information at a higher density in or from a medium.

A near-field optical head device according to another aspect of the present invention includes: the near-field optical head; and a suspension structure supporting the slider to keep constant the distance between the end of the scattering member and the medium when recording information in the medium using the near field light by the scattering member.

The near-field optical head device includes the suspension structure supporting the slider to keep constant the distance between the end of the scattering member and the medium when recording information in the medium using the near field light by the scattering member. This makes it possible to miniaturize the near-field optical head device capable of stably recording or reproducing information at a higher density in or from a medium using the small near-field optical head.

A near-field optical information device according to still another aspect of the present invention includes: the near-field optical head device; and an electric circuit receiving a signal obtained from the near-field optical head device and controlling and driving the light source based on the signal.

The near-field optical information device can receive a signal obtained from the near-field optical head device and control and drive the light source based on the signal, thereby miniaturizing the near-field optical information device capable of stably recording or reproducing information at a higher density in or from a medium using the small near-field optical head device.

A near-field optical information system according to still another aspect of the present invention includes: the near-field optical information device; and an arithmetic unit making a predetermined calculation based on information recorded in or reproduced from the medium by the near-field optical information device.

The near-field optical information system can make a predetermined calculation based on information recorded in or reproduced from the medium by the near-field optical information device, thereby miniaturizing the near-field optical information system capable of making diverse calculations using information more densely and stably recorded or reproduced in or from a medium.

BEST MODE FOR IMPLEMENTING THE INVENTION

Each embodiment of the present invention will be below described with reference to the drawings.

First, a configuration and an operation according to a first embodiment of the present invention will be described with reference toFIGS. 1 to 4.FIG. 1is a schematic side view of a near-field optical information system according to the first embodiment.

InFIG. 1, reference numeral1denotes an optical disk as a medium (recording medium) formed with a phase-change material for recording or reproducing information;2, a spindle motor holding and rotating the optical disk1at a predetermined speed; and 3, a near-field optical head for recording or reproducing information in or from the optical disk1which corresponds to the near-field optical probe slider and optical head according to the prior art.

Reference numeral4designates a suspension supporting the near-field optical head3to keep the distance between the near-field optical head3and the optical disk1constant in the directions of F (focusing) perpendicular to the optical disk1;5, a motor holding the suspension4and revolving to thereby move the near-field optical head3in the directions of T (tracking) flush and parallel with the optical disk1;6, an electric circuit controlling and driving a semiconductor laser element31(described later: seeFIGS. 3A and 3B) as a light source, the spindle motor2, the motor5or the like on the basis of a signal obtained from the near-field optical head3; and7, an arithmetic unit making a predetermined calculation based on information recorded in or reproduced from the optical disk1through the electric circuit6.

The arithmetic unit7processes information on data, visuals, audio and the like. The above component elements constitute the near-field optical information system according to this embodiment; the component elements other than the arithmetic unit7, the near-field optical information device; and the component elements further excluding the electric circuit6, the near-field optical head device.

FIG. 2is a perspective exploded view showing a configuration of the suspension4ofFIG. 1. As shown inFIG. 2, the near-field optical head device includes the near-field optical head3, a gimbal4a, the suspension4and a fixing plate5a. The suspension4is fixed so as to turn freely at one end to the motor5(seeFIG. 1) via the fixing plate5aand fixed at the other end to the near-field optical head3via the gimbal4a. This configuration allows the suspension4to support the near-field optical head3with keeping the distance from the optical disk1constant, for example, using an art similar to a flying head employed for a hard-disk drive in a magnetic head mechanism disclosed by Japanese Unexamined Patent Publication No. 7-1616.

FIGS. 3A and 3Bare top and side views, respectively, showing a configuration of the near-field optical head ofFIG. 1. InFIGS. 3A and 3B, reference numeral1denotes an optical disk as a medium for recording or reproducing information;31, a semiconductor laser element as a light source emitting, for example, in this embodiment, a radiant beam LB having a wavelength of 800 nm and a power of 50 mW and polarized in the F-directions;32, a prism as a light guiding member transmitting the radiant beam LB of the semiconductor laser element31; and33, a scattering member having a substantially flat-plane shape and two first and second planes P1and P2substantially perpendicular to the optical disk1. The scattering member33is substantially perpendicularly irradiated with the radiant beam LB passing through the prism32to thereby generate near field light NL in a part PA proximate to the optical disk1and apply it to the optical disk1.

Reference numeral34designates a copper heat dissipation material fixed to the semiconductor laser element31and conducting and dissipating generated heat;35, a photodetector element detecting light reproduced from the optical disk1; and36, a slider holding the semiconductor laser element31, the prism32, the scattering member33, the heat dissipation material34and the photodetector element35. These component elements constitute a so-called near-field optical probe slider as the near-field optical head3.

Reference numeral37denotes a molding resin and the semiconductor laser element31, the prism32, the scattering member33, the heat dissipation material34and the photodetector element35are bonded and fixed to the slider36. The molding resin37is molded into a gap between the slider36and the semiconductor laser element31, the prism32, the scattering member33, the heat dissipation material34and the photodetector element35.

FIG. 4is a view seen from an arrow B ofFIG. 3B. The conductive scattering member33is formed, as shown inFIG. 4, by a scattering body33ahaving a substantially flat-plane shape provided with the second plane P2and the first plane P1reverse to the second plane P2, and a holding member33bhaving a substantially flat-plane shape. The scattering body33ais fixed and held to the holding member33band fixed to the slider36via the holding member33b. The scattering body33ais made of a material generating plasmon light easily, for example, gold, titanium, chromium, silver, copper, aluminum or the like, and the optical disk1is made of, for example, a phase-change record material formed of an alloy of TbFeCo (terbium, iron, cobalt) or the like, or another material.

The slider36is supported by the suspension4in such a way that the distance between a tip PA of the scattering body33aheld on the slider36and the optical disk1comes within an effusion depth of the near field light NL. In this state, the scattering body33agenerates the near field light NL from the tip PA. The distance between the tip PA of the scattering body33aand the optical disk1is preferably below tens of nanometers, more desirably below several nanometers, and for example, is 10 nm in this embodiment.

In this embodiment, in order to increase the effusion quantity of the near field light NL, a center Z of the radiant beam LB is brought to substantially the gravity center of the scattering body33agenerating the near field light NL in the scattering member33. The near field light NL changes the crystal phase of the optical disk1provided with the phase-change material into an amorphous phase to thereby form a record mark. On the other hand, information is reproduced by allowing the photodetector element35to detect a variation in the intensity of reflected light returning from the optical disk1, in further detail, because the percentage of the near field light NL scattered from the optical disk1varies according to the presence of the record mark, detect a variation in the intensity of the scattered light as the reflected light from the optical disk1.

Specifically, the scattering body33ais a substantially triangular flat plane and has the first plane P1perpendicular to the recording surface or reproduction surface of the medium1on the side of the semiconductor laser element31and the second plane P2parallel to the first plane P1. The slider36holds the scattering member33in such a way that the tip PA of the first plane P1is proximate to the medium1. In this state, the radiant beam LB from the semiconductor laser element31irradiates the whole first plane P1perpendicularly through the prism32, and the scattering member33has a pointed shape and applies the near field light NL to the medium1from the tip PA of the pointed shape.

At this time, the semiconductor laser element31is arranged on the bottom side of the slider36to thereby bring the center Z of the radiant beam LB from the semiconductor laser element31as exactly as possible to the gravity center of the scattering body33a. This makes it possible to irradiate the scattering body33awith as great optical energy as possible and thereby for the scattering body33ato generate plasmon light sufficiently. The shape of the scattering body33ais not limited especially to the above example, as long as it generates the near field light NL efficiently.

In this embodiment, therefore, the configuration of the recording optical system becomes simpler by applying the radiant beam LB from the semiconductor laser element31perpendicularly to the first plane P1perpendicular to the medium1, and the configuration of the reproduction optical system becomes simpler by detecting light reproduced from the optical disk1directly because the photodetector element35faces the second plane P2opposite to the first plane P1of the scattering body33airradiated with the radiant beam LB from the semiconductor laser element31. This makes it possible to miniaturize the near-field optical head3sufficiently, thereby controlling the distance between the scattering body33aand the optical disk1with a high precision using a similar art to a flying head employed for a hard-disk drive, and recording or reproducing information at a high density in or from the optical disk1by utilizing plasmon light.

For example, if the scattering body33ais a conductive metal having a base (long side of the junction surface to the holding member33b) of 300 nm, a height (length in the F-directions) of 400 nm and a curvature radius of 25 nm at the tip and if the semiconductor laser element31is a laser chip having measurements of 200 μm (width)×250 μm (depth)×90 μm (height), the head part except the slider36becomes approximately 2 mm×5 mm, thereby miniaturizing the slider36or the near-field optical head3up to a size of about 5 mm×5 mm.

Furthermore, in this embodiment, the semiconductor laser element31is the small laser chip and the heat dissipation material34has a surface area for sufficiently dissipating heat generated by the laser chip, thereby enabling the semiconductor laser element31to operate continuously and stably and keeping the distance between the scattering body33aand the optical disk1precisely constant by preventing each component element from being thermally expanded and deformed unexpectedly while the semiconductor laser element31is in continuous operation. Alternatively, it may be appreciated that the heat dissipation material34is thermally connected to the suspension4, thereby allowing the heat dissipation material34to dissipate heat more effectively.

In the first embodiment, therefore, the slider36holds the semiconductor laser element31and the heat dissipation material34, the prism32, the scattering member33and the photodetector element35to form the so-called near-field optical probe slider, thereby realizing the significantly miniaturized near-field optical head device capable of recording or reproducing information at a high density using the near field light NL for the optical disk1. Besides, the first embodiment is provided with the heat dissipation material34, thereby solving the heat-generation problem of the semiconductor laser element31as well.

The first embodiment is provided among the component elements with the heat dissipation material34and the photodetector element35. However, the purport of the present invention is not vitiated even without them.

Moreover, in the first embodiment, the suspension4supports the slider36(the near-field optical head3) and the motor5holds and rotates the suspension4to thereby make a recording or a reproduction over the whole area of the optical disk1. However, the present invention is not limited to this configuration, as long as the slider36is supported to keep the distance between the scattering body33aand the optical disk1below tens of nanometers as well as moves throughout the whole area of the optical disk1.

In addition, in the first embodiment, the optical disk1is rotated by the spindle motor2to thereby record or reproduce information. Alternatively, it may be appreciated that an optical card substituted for the optical disk1is fixed without rotating and the slider36moves over the whole area of the optical card as a medium, thereby recording or reproducing information. The configuration of such an optical card device vitiates the purport of the present invention.

Furthermore, in the first embodiment, the prism32guides the radiant beam LB of the semiconductor laser element31to the scattering body33a. However, the prism32may be omitted to apply the radiant beam LB of the semiconductor laser element31directly to the scattering body33a.

Next, a description will be given of a near-field optical information system according to a second embodiment of the present invention. This embodiment is different in a near-field optical head from the first embodiment, however otherwise the same, and thus, a configuration and an operation will be described only about the near-field optical head.FIGS. 5A and 5Bare top and side views, respectively, showing a configuration of the main part of the near-field optical head according to the second embodiment.

InFIGS. 5A and 5B, all the component elements and functions and operations thereof are almost the same as the first embodiment. However, the semiconductor laser element31is fixed at an angle to a prism32a, thereby applying the radiant beam LB more easily to the tip PA of the scattering body33a.

The prism32ahas an emission plane EP parallel to the first plane P1of the scattering body33aand an incidence plane IP inclined with respect to the emission plane EP which fixes the semiconductor laser element31. The prism32aleads the radiant beam LB of the semiconductor laser element31obliquely downward, thereby easily irradiating the entire first plane P1of the scattering body33a.

FIG. 6is a view seen from an arrow B ofFIG. 5B. In order to bring the center Z of the radiant beam LB from the semiconductor laser element31exactly to the gravity center of the scattering body33a, as shown inFIG. 6, the radiant beam LB is guided obliquely downward by the prism32aand irradiates the whole first plane P1substantially perpendicularly, thereby irradiating the scattering body33awith greater optical energy and thus enabling the scattering body33ato generate plasmon light further sufficiently.

In the second embodiment, therefore, the center Z of the radiant beam LB substantially coincides more easily with the scattering body33agenerating the near field light NL in the scattering member33, thereby further increasing the effusion quantity of the near field light NL. Besides, the heat dissipation material34is farther above the slider36, thereby allowing the heat dissipation material34to dissipate heat more effectively.

Next, a description will be given of a near-field optical information system according to a third embodiment of the present invention. This embodiment is different in a near-field optical head from the first embodiment, however otherwise the same, and thus, a configuration and an operation will be described only about the near-field optical head.FIG. 7is a side view showing a configuration of the main part of the near-field optical head according to the third embodiment.

InFIG. 7, the basic configuration is the same as the first embodiment, and reference numeral31denotes a semiconductor laser element; reference numeral and character32b, a prism transmitting the radiant beam LB of the semiconductor laser element31; and34a, a copper heat dissipation material. The prism32bhas an optical reflection plane RP reflecting the radiant beam LB from the semiconductor laser element31and leading it to the scattering member33. In other words, the radiant beam LB from the semiconductor laser element31is incident from above upon the prism32b, reflected by the optical reflection plane RP and guided obliquely downward.

The view seen from an arrow B ofFIG. 7is similar toFIG. 6. In order to bring the center Z of the radiant beam LB exactly to the gravity center of the scattering body33a, the radiant beam LB from the semiconductor laser element31is guided obliquely downward by the optical reflection plane RP and irradiates the whole first plane P1substantially perpendicularly, thereby irradiating the scattering body33awith greater optical energy and thus enabling the scattering body33ato generate plasmon light further sufficiently.

In the third embodiment, therefore, the optical reflection plane RP makes it easier to bring the center Z of the radiant beam LB substantially to the scattering body33agenerating the near field light NL in the scattering member33, thereby further increasing the effusion quantity of the near field light NL. Besides, in the third embodiment, the heat dissipation material34ais arranged above the prism32b. This makes it possible to arbitrarily enlarge the heat dissipation material34acompared with the first embodiment, thereby solving the heat-generation problem of the semiconductor laser element31more easily.

Next, a description will be given of a near-field optical information system according to a fourth embodiment of the present invention. This embodiment is different in a near-field optical head from the first embodiment, however otherwise the same, and thus, a configuration and an operation will be described only about the near-field optical head.FIG. 8is a side view showing a configuration of the main part of the near-field optical head according to the fourth embodiment.

InFIG. 8, the basic configuration is the same as the first embodiment, and reference numeral31designates a semiconductor laser element; reference numeral and character32c, a prism transmitting the radiant beam LB of the semiconductor laser element31;32d, an optical waveguide; and34a, a copper heat dissipation material. The optical waveguide32dunited to the bottom of the prism32receives the radiant beam LB from the semiconductor laser element31and leads it inside to the scattering body33a. In other words, the radiant beam LB from the semiconductor laser element31is incident from above upon the prism32cand guided along the bottom of the prism32by the optical waveguide32d.

FIG. 9is a view seen from an arrow B ofFIG. 8. As shown inFIG. 9, the radiant beam LB is converted into a flat beam and guided along the bottom of the prism32by the optical waveguide32dand irradiates the whole first plane P1substantially perpendicularly in such a way that the center Z coincides with the gravity center of the scattering body33a, thereby irradiating the scattering body33awith far greater optical energy and thus enabling the scattering body33ato generate plasmon light still further sufficiently.

In the fourth embodiment, therefore, the optical waveguide32dmakes it easier to bring the center Z of the radiant beam LB substantially to the scattering body33agenerating the near field light NL in the scattering member33, thereby further increasing the effusion quantity of the near field light NL. Further, in the fourth embodiment, the optical waveguide32dconverts the radiant beam LB into a flat beam and applies it to the scattering body33a, thereby raising the irradiation power per irradiation area in an irradiation position of the scattering body33a. Still further, in the fourth embodiment, the heat dissipation material34ais arranged above the prism32b. This makes it possible to arbitrarily enlarge the heat dissipation material34acompared with the first embodiment, thereby solving the heat-generation problem of the semiconductor laser element31more easily.

Next, a description will be given of a near-field optical information system according to a fifth embodiment of the present invention. This embodiment is different in a near-field optical head from the first embodiment, however otherwise the same, and thus, a configuration and an operation will be described only about the near-field optical head.FIG. 10is a side view showing a configuration of the main part of the near-field optical head according to the fifth embodiment.

InFIG. 10, the basic configuration is the same as the first embodiment, and reference numeral31denotes a semiconductor laser element; reference numeral and character32e, a prism transmitting the radiant beam LB of the semiconductor laser element31; and34a, a copper heat dissipation material. The prism32ehas an optical reflection plane RP and a lens surface LP. The radiant beam LB from the semiconductor laser element31is reflected by the optical reflection plane RP, guided toward and incident upon the lens surface LP, converged by a lens effect of the lens surface LP and led to the scattering member33. In short, the radiant beam LB from the semiconductor laser element31is incident from above upon the prism32e, reflected by the optical reflection plane RP, converged by the lens surface LP and led to the scattering member33. The lens surface LP is formed by making the prism32eout of two materials having a mutually-different refractive index or by providing a diffraction plane, however, the formation thereof is not limited to those.

FIG. 11is a view seen from an arrow B ofFIG. 10. As shown inFIG. 11, the radiant beam LB is guided obliquely downward by the optical reflection plane RP, converged by the lens surface LP and applied substantially perpendicularly to the whole first plane P1in such a way that the center Z coincides with the gravity center of the scattering body33a, thereby irradiating the scattering body33awith even greater optical energy and thus enabling the scattering body33ato generate plasmon light still further sufficiently.

In the fifth embodiment, therefore, the optical reflection plane RP and the lens surface LP make it easier to bring the center Z of the converged radiant beam LB substantially to the scattering body33agenerating the near field light NL in the scattering member33, thereby further increasing the effusion quantity of the near field light NL. Further, in this embodiment, the lens surface LP converges the radiant beam LB and applies it to the scattering body33a, thereby raising the irradiation power per irradiation area in an irradiation position of the scattering body33a. Still further, in the fifth embodiment, the heat dissipation material34ais arranged above the prism32b. This makes it possible to arbitrarily enlarge the heat dissipation material34acompared with the first embodiment, thereby solving the heat-generation problem of the semiconductor laser element31more easily.

In each embodiment described so far, the scattering member33is formed by the scattering body33aand the holding member33b, however, the present invention is not limited especially to this example. Alternatively, it may be appreciated that the whole of a scattering member is made, without the holding member33b, of a material generating plasmon light easily, such as gold, titanium and chromium. Besides, the shape of a scattering body is variable, for example, a scattering member33′ shown inFIGS. 12A and 12Bmay also be employed.

As shown inFIGS. 12A and 12B, the scattering member33′ is formed by a scattering body33cand the holding member33b. The scattering body33cis fixed and held to the holding member33band fixed to the slider36via the holding member33b. The scattering body33cincludes a first plane P1perpendicular to the recording surface or reproduction surface of the medium1on the side of the semiconductor laser element31and a second plane P2opposite to and inclined with respect to the first plane P1and has a pointed shape both in front and side views.

The radiant beam LB from the semiconductor laser element31irradiates the whole first plane P1substantially perpendicularly in such a way that the center Z coincides with the gravity center of the scattering body33c, and the scattering body33capplies the near field light NL from a sharp tip PA thereof to the medium1. The pointed shape both in front and side views makes the near field light NL denser, thereby causing the scattering body33cto generate plasmon light more intensely.

On the basis of each embodiment described so far, the present invention is summarized as follows. A near-field optical head according to an aspect of the present invention includes: a light source; a scattering member having a substantially flat-plane shape; and a slider holding the light source and the scattering member, in which: the slider holds the scattering member in such a way that an end of the scattering member is proximate to a medium; the scattering member has a first plane located on the side of the light source and substantially perpendicular to the medium; light emitted from the light source irradiates the first plane substantially perpendicularly; and the end of the scattering member generates near field light and applies the near field light to the medium.

The near-field optical head can apply light emitted from the light source substantially perpendicularly to the first plane of the scattering member substantially perpendicular to the medium to thereby generate near field light from the end of the scattering member and apply it to the medium. This makes it possible to simplify the configuration of a recording optical system and significantly miniaturize the near-field optical head capable of recording or reproducing information at a higher density in or from a medium.

It is preferable that: a light guiding member is further provided which transmits the light emitted from the light source and leads the light to irradiate the first plane substantially perpendicularly; and the slider holds the light source, the scattering member and the light guiding member.

In this case, the light emitted from the light source passes through the light guiding member and irradiates the first plane substantially perpendicularly. This makes it possible to irradiate the scattering member with greater optical energy and thereby for the end of the scattering member to generate plasmon light sufficiently.

It is preferable that: the scattering member may include a substantially flat-plane shaped conductive scattering body having the first plane and generating the near field light, and a holding member holding the scattering body; and the light guiding member may transmit the emitted light from the light source in such a way that the emitted light from the light source irradiates the whole first plane of the scattering body.

In this case, the light emitted from the light source can pass through the light guiding member and irradiate the whole surface of the scattering body generating the near field light, thereby generating plasmon light sufficiently and stably from the scattering body.

Preferably, the scattering body may have a pointed shape and apply the near field light to the medium from the tip of the pointed shape.

In this case, the near field light can irradiate the medium from the tip of the pointed shape of the scattering body, thereby making the near field light denser to generate plasmon light more intensely from the scattering body.

Preferably, the light guiding member may be an optical element having an optical reflection plane for reflecting the emitted light from the light source in such a way that the emitted light from the light source irradiates the whole first plane of the scattering body.

In this case, the emitted light from the light source can be easily guided down obliquely in such a way that the emitted light irradiates the whole surface of the scattering body, thereby further increasing the effusion quantity of the near field light. Besides, the heat dissipation member conducting heat generated by the light source can be arranged above the light guiding member, thereby enlarging the heat dissipation member arbitrarily to dissipate the generated heat from the light source more easily.

Preferably, the light guiding member may be an optical element having a light guiding function of guiding the emitted light from the light source in such a way that the emitted light from the light source irradiates the whole first plane of the scattering body.

In this case, the emitted light from the light source can be converted into a flat beam and guided along the bottom of the light guiding member, thereby irradiating the whole surface of the scattering body with greater optical energy to further increase the effusion quantity of the near field light. Besides, the heat dissipation member conducting heat generated by the light source can be arranged above the light guiding member, thereby enlarging the heat dissipation member arbitrarily to dissipate the generated heat from the light source more easily.

Preferably, the light guiding member may be an optical element having a function of converging the emitted light from the light source in such a way that the emitted light from the light source irradiates the whole first plane of the scattering body.

In this case, the converged emitted light can irradiate the whole surface of the scattering body with greater optical energy, thereby further increasing the effusion quantity of the near field light.

It is preferable that: a heat dissipation member is further provided which is fixed to the light source and conducts heat generated by the light source; and the slider holds the light source, the light guiding member, the scattering member and the heat dissipation member.

This makes it possible to miniaturize the near-field optical head including the heat dissipation member and dissipate heat generated from the light source sufficiently, thereby enabling the light source to operate continuously and stably and keeping the distance between the scattering member and the medium precisely constant by preventing each component element from being thermally expanded and deformed unexpectedly while the light source is in continuous operation.

It is preferable that: a photodetector is further provided which faces a second plane of the scattering member opposite to the first plane; and the slider holds the light source, the light guiding member, the scattering member and the photodetector.

In this case, the photodetector can directly detect light reproduced from the medium, thereby simplifying the reproduction optical system to make the near-field optical head smaller.

A near-field optical head device according to another aspect of the present invention includes: the near-field optical head; and a suspension structure supporting the slider to keep constant the distance between the end of the scattering member and the medium when recording information in the medium using the near field light by the scattering member.

The near-field optical head device includes the suspension structure supporting the slider to keep constant the distance between the end of the scattering member and the medium when recording information in the medium using the near field light by the scattering member. This makes it possible to miniaturize the near-field optical head device capable of stably recording or reproducing information at a higher density in or from a medium using the small near-field optical head.

Preferably, a drive mechanism may be further provided which drives the suspension structure in one direction on a plane parallel to the medium.

This makes it possible to widen the part available as a recording or reproduction surface of the medium, thereby increasing the amount of information which can be recorded or reproduced.

Preferably, the distance between the end of the scattering member and the medium may be within an effusion depth of the near field light, thereby recording or reproducing information stably using the near field light.

A near-field optical information device according to still another aspect of the present invention includes: the near-field optical head device; and an electric circuit receiving a signal obtained from the near-field optical head device and controlling and driving the light source based on the signal.

The near-field optical information device can receive a signal obtained from the near-field optical head device and control and drive the light source based on the signal, thereby miniaturizing the near-field optical information device capable of stably recording or reproducing information at a higher density in or from a medium using the small near-field optical head device.

It is preferable that: a rotation mechanism is further provided which rotates the medium; and the electric circuit receives a signal obtained from the near-field optical head and controlling and driving the rotation mechanism and the light source based on the signal.

This makes substantially the whole surface of the medium usable as a recording or reproduction surface, thereby significantly increasing the amount of information which can be recorded or reproduced.

A near-field optical information system according to still another aspect of the present invention includes: the near-field optical information device; and an arithmetic unit making a predetermined calculation based on information recorded in or reproduced from the medium by the near-field optical information device.

The near-field optical information system can make a predetermined calculation based on information recorded in or reproduced from the medium by the near-field optical information device, thereby miniaturizing the near-field optical information system capable of making diverse calculations using information more densely and stably recorded or reproduced in or from a medium.

The near-field optical head according to the present invention is configured by holding the light source and the scattering body at least on the slider, or together with those component elements, holding the light guiding member, the heat dissipation member or the photodetector thereon, and is capable of recording or reproducing information at a higher density in or from a medium using near field light with significantly miniaturized. Further, the near-field optical information device provided with the near-field optical head device including the near-field optical head is capable of recording or reproducing high-density and large-capacity information in or from a medium. Still further, the near-field optical information system provided with the arithmetic unit can be widely applied to every near-field optical information system which stores information from the arithmetic unit as information on data, visuals or audio, such as a computer, an optical disk player, an optical disk recorder, a car navigation system, an editing system, a data server and an AV component.