KR100618977B1 - Optical head for near field recording/reproducing by using vertical cavity surface emitting laser - Google Patents

Abstract

A surface light laser and a near field employing the same are provided with a lens portion in the form of a Fresnel pattern on the side of the window from which the laser light is emitted, so that the emitted laser light is diffracted while passing through the lens portion and focused at an adjacent position. Disclosed is an optical head for recording and reproducing.

In this way, the surface light laser having the lens portion is a converging light having a focus at a position where light emitted therefrom is proximate from the window. Therefore, an optical head for near field recording and reproduction employing such a surface light laser as a light source is provided with a separate lens member or the like. Since the near field recording and reproducing can be performed by mounting a surface light laser directly on the slider without the optical element of the optical element, a simple structure, no separate optical alignment is required, and a miniaturized near field recording and reproducing optical head can be realized.

Description

Optical head for near field recording / reproducing by using vertical cavity surface emitting laser

1 is a view schematically showing the configuration of a general near field recording and reproducing apparatus;

2 is a view schematically showing the configuration of an optical head in FIG.

3 is a cross-sectional view schematically showing a laminated structure of a surface light laser according to an embodiment of the present invention;

4 is a cross-sectional view schematically showing a laminated structure of a surface light laser according to another embodiment of the present invention;

5 is a plan view of FIGS. 3 and 4;

6 is a cross-sectional view schematically showing a laminated structure of a general surface light laser,

7 is a schematic view of an optical head for near field recording and reproducing according to an embodiment of the present invention;

8 is a schematic view showing an optical head for near field recording and reproducing according to another embodiment of the present invention;

9 and 10 are a plan view showing an embodiment of the optical module of Figure 8, respectively;

Figure 11 is a schematic cross-sectional view of one embodiment of an optical module according to the present invention.

<Description of the symbols for the main parts of the drawings>

20 ... slider 50,150 ... surface light laser

51,61 ... first and second electrodes 55,59 ... first and second reflector layers

60,160 ... Lens section 70,170 ... Recording medium

71,171 ... Recording layer 73,173 ... Substrate

80,180 ... Photodetector 155 ... Trench

185,187,189 ... first to third semiconductor material layers 191,195

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a surface emitting laser in which a focusing means is integrated and an optical head for near field recording and reproduction employing the same.

In general, the near field refers to a technique for performing recording and reproduction of data in a state where the distance between the optical element and the recording medium disposed in proximity to the recording medium such as an optical disc is close to, for example, about 20 to 300 nm.

1 and 2, a general near field recording and reproducing apparatus includes a swing arm 21 reciprocally rotatable with respect to a base, an actuator 23 providing a rotation driving force to the swing arm 21, and pneumatic pressure. And a slider 25 provided at the end of the swing arm 21 and the slider 25 so as to scan the track of the optical disk 10 while being floated with respect to the optical disk 10 by means of an optical information. And an optical head 30 forming an optical spot on the optical disk 10 so that the optical disk 10 can reproduce. Here, the optical disk includes a phase change type optical disk and an optical magnetic disk. When the optical magnetic disk is employed as the optical disk, the optical head 30 further includes a coil 35 for magnetic field modulation.

The optical head 30 is composed of a light transmitting / receiving part 40, a reflecting mirror 32, an objective lens 33, and a solid immersion lens (SIL) or a solid immersion mirror (SIM). It comprises a small lens 34.

2 illustrates an apparatus employing a refractive-type solid-impregnated lens as the small lens 34, and the small lens 34 is configured to focus light irradiated from the transmitting and receiving part 40 onto the optical disk 10 at a large incident angle. do. As a result, the size of the light spot formed on the optical disc 10 can be reduced.

The transmitter / receiver 40 includes a bandore laser, a photodetector, and an optical path converting means. In this case, the light path converting means converts the light emitted from the semiconductor laser toward the reflective mirror 32 and the light reflected from the optical disc 10 returns to the photodetector.

The transmitter / receiver 40 irradiates laser light having a diameter suitable for the objective lens 33, and the reflection mirror 32 reflects the light incident from the transmitter / receiver 40 toward the objective lens 33. The objective lens 33 focuses incident light onto the small lens 34, and the small lens 34 forms a near field on the optical disk 10.

The slider 25 is biased in the direction in which the suspension 26 is in contact with the optical disc 10. The slider 25 is floated from the optical disk 10 by the pneumatic pressure when the optical disk 10 starts to rotate, and the air gap G between the optical element 34 and the optical disk 10 is formed. ) Should be a close distance of about 20 to 300 nm as described above, which is smaller than the wavelength of the light emitted from the light-receiving unit 40, so that the size of the light spot formed on the optical disc 10 is close to the desired light spot size.

However, the recording and reproducing apparatus as described above includes a plurality of optical elements for concentrating light from the transmitting / receiving unit 40 at a relatively long distance and condensing on the optical disc 10. Therefore, the structure of the recording and reproducing apparatus is complicated. Not only is the optical alignment from 40 to the small lens 34 difficult, but also its size is difficult to miniaturize.

The present invention has been made in view of the above-mentioned point, and the surface light laser which can focus the output laser light directly to the near field by integrating the focusing means, and adopting the same, the structure is simplified and the optical alignment is easy and can be miniaturized. It is an object of the present invention to provide an optical head for near field recording and reproduction.

The present invention in order to achieve the above object; A first reflector layer formed on the substrate; An active layer formed on the first reflector layer to generate light by recombination of electrons and holes; A second reflector layer formed on the active layer; A first electrode formed on the bottom surface of the substrate; And a second electrode formed on the second reflector layer, wherein the surface light laser generates and emits laser light in a stacking direction of the semiconductor material layer, wherein the laser light is emitted in a Fresnel pattern form on a window side. It is characterized in that it is provided with a lens portion, so that the laser light emitted is diffracted while passing through the lens portion to be focused at a proximal position.

In this case, the lens unit is preferably formed by etching a portion of the second reflector layer in the form of a Fresnel pattern.

In addition, in order to achieve the above object, the present invention is installed in a slider moving on the recording medium while being floated by the air dynamic pressure generated by the rotation of the recording medium, the near field which can record and reproduce information through optical and / or magnetic field modulation. An optical head for recording and reproducing, wherein the recording medium includes a recording layer and a transparent substrate supporting the recording layer and transmitting incident light, the substrate being provided on the slider; A first electrode formed on the bottom surface of the substrate; A first reflector layer formed on the substrate; An active layer formed on the first reflector layer; A second reflector layer formed on the active layer; A second electrode formed on the second reflector layer; And a lens unit provided in the form of a Fresnel pattern on the side of the window so that the emitted laser light is focused at a position proximate to the diffraction focus. A surface light laser focusing on; And a photodetector facing the surface light laser so as to receive light incident on the recording layer from the surface light laser via the lens portion and transmitted through the transparent substrate.

In addition, in order to achieve the above object, the present invention is installed on the slider moving on the recording medium while being floated by the air dynamic pressure generated by the rotation of the recording medium to record and reproduce information through optical and / or magnetic field modulation. An optical head for near field recording and reproducing, the recording medium comprising: a substrate having a recording layer and a reflecting layer supporting the recording layer and reflecting incident light, the substrate being provided on the slider; A first electrode formed on the bottom surface of the substrate; A first reflector layer formed on the substrate; An active layer formed on the first reflector layer; A second reflector layer formed on the active layer; A second electrode formed on the second reflector layer; And a lens unit provided in the form of a Fresnel pattern on the side of the window so that the emitted laser light is focused at a position proximate to the diffraction focus. The laser unit generates and emits laser light in the stacking direction of the semiconductor material layer and is located close to the window. A surface light laser focusing on; And a photodetector provided at one side of the surface light laser to receive light focused from the surface light laser to the recording layer via the lens portion and reflected from the reflective layer, wherein the Fresnel pattern of the lens portion is the center of the pattern. It is provided so as to be positioned away from the center of the window, at least a portion of the laser light is incident to the recording layer at an oblique angle and then reflected from the reflective layer to be directed to the photodetector.

In this case, the lens unit is preferably formed by etching a portion of the second reflector layer in the form of a Fresnel pattern.

According to an aspect of the present invention, a coil member is further provided between the slider and the recording medium and / or under the recording medium, and is provided to record and reproduce the signal by light and magnetic field modulation, and is incident on the light receiving surface of the photodetector. It further comprises a pair of polarizing members for dividing the light spot to be approximately two to transmit different polarization components.

In this case, the pair of polarizing members, the pattern direction is perpendicular to each other and the pattern interval is preferably holographic grating formed smaller than the emission wavelength of the surface light laser.

The photodetector may share a substrate of the surface light laser and a first electrode formed on the bottom surface of the substrate, and may be electrically insulated from the surface light laser laterally on the substrate. It is preferable to provide a detection pattern of a predetermined pattern in at least some regions except for the above, and the photodetector has substantially the same material composition and number of stacked layers as the first reflector layer, and at least a portion thereof is spaced apart from the surface light laser by a predetermined distance. A first semiconductor material layer formed to be; A second semiconductor material layer formed on the first semiconductor material layer and made of substantially the same material and thickness as the active layer; And a third semiconductor material layer formed on the second semiconductor material layer and having a material configuration substantially the same as that of the second reflector layer, and having a smaller number of stacks than the second reflector layer. The laser and photodetector may be integrally formed on the same semiconductor manufacturing process.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

3 is a cross-sectional view schematically showing a laminated structure of a surface light laser according to an embodiment of the present invention.

Referring to the drawings, the surface light laser 50 according to the present invention includes a substrate 53 and a first reflector layer 55, an active layer 57, and a second reflector layer sequentially stacked on the substrate 53. 59, a first electrode 51 formed on the bottom surface of the substrate 53, a second electrode 61 formed on the second reflector layer 59, and a window 63 through which laser light is emitted. It is comprised including the lens part 60 provided in the side.

The substrate 53 is an intrinsic semiconductor substrate or a semiconductor substrate doped with one type. The first and second reflector layers 55 and 59 are formed by alternately stacking semiconductor compounds, and are doped with impurities of different types. In this case, since the reflectance depends on the number of stacked semiconductor compounds, as shown in FIG. 3, in the case of the structure in which the laser light is mostly emitted through the second reflector layer 59, the second reflector layer 59 is The stacking number is smaller than that of the first reflector layer 55. Here, when the substrate 53 is n-type, the first reflector layer 55 is n-type, the second reflector layer 59 is doped with p-type impurities, respectively.

The active layer 57 is a region where light is generated by recombination of electrons and holes. A portion of the active layer 57 and / or the second reflector layer 59 guides the flow of current so that the current is active layer 57. It is preferable that the high resistance portion 58 is further formed so as to flow to the center portion. The high resistance portion 58 may be formed by ion implantation, selective oxidation, or the like. Since the technique for forming the high resistance portion 58 is well known, a detailed description thereof will be omitted.

The first electrode 51 is formed on the bottom surface of the substrate 53, and the second electrode 61 is formed in an area excluding the window 63 from which light is emitted on the second reflector layer 59.

Here, reference numeral 56 is an insulating layer formed in an area except for a portion where the window 63 and the second electrode 61 and the second reflector layer 59 are electrically connected to each other.

In this structure, when a current is injected through the second electrode 61, the current is injected into the surface light laser 50 through the window 63.

Alternatively, as shown in FIG. 4, the second electrode 61 may be formed on the second reflector layer 59 including the window 63 and its periphery using a transparent electrode such as ITO. In this case, since the current can be more evenly injected into the center portion 57a of the active layer 57, there is an advantage that a better laser beam profile can be obtained.

In the present exemplary embodiment, the lens unit 60 is formed by etching a portion of the second reflector layer 59 in the form of a Fresnel pattern, as shown in FIG. 5. The Fresnel pattern refers to a hologram pattern etched in the form of Fresnel lens or Fresnel zone.

When the lens unit 60 is provided in this way, the light emitted through the second reflector layer 59 is focused by diffraction while passing through the lens unit 60 and focused at a position proximate to the surface light laser 50. . In this case, the focus position of the focused laser light may be changed by changing the spacing of the Fresnel patterns.

3 to 5 illustrate the center of the pattern such that the diffracted condensed light via the Fresnel pattern of the lens unit 60 has a symmetrical structure about the center axis c of the window 63, that is, the optical axis. Although the example is formed to be located on the window (63) central axis (c), it can be formed differently depending on the application.

For example, when the light emitted from the surface light laser 50 is to be focused at a position other than on the window 63 center axis c, as shown in FIGS. 9 and 10 to be described later, The Fresnel pattern may be formed so that the center of the pattern deviates from the center axis c of the window 63.

Alternatively, the lens unit 60 may include a separate member having a Fresnel pattern formed close to the window 63 instead of forming a portion of the second reflector layer 59 by etching a predetermined pattern. It may be.

In the surface light laser 50 according to the present invention as described above, when forward bias is applied to the first and second electrodes 61, current flows through the central portion 57a of the active layer 57, and Electrons and holes generated in the second reflector layers 55 and 59 are recombined in the active layer 57 to generate light. Of the light, between the first and second reflector layers 55 and 59, only light of a specific wavelength (resultingly emitted laser light) that survives and amplifies and amplifies, and mostly exits through the window 63. The lens unit 60 is diffracted at the lens unit 60 in the form of a Fresnel pattern, and is focused at an adjacent focal point f.

At this time, when the lens unit 60 is formed by etching a part of the second reflector layer 59 in a Fresnel pattern, the light along the unetched protruding region 60a among the light generated in the active layer 57 is It is resonated and amplified between the first and second reflector layers 55 and 59. On the contrary, since the reflectance and the resonance condition change sensitively to the number of stacked layers of the reflector layer, the region (hatched area 60b) where the partial layer of the second reflector layer 59 is etched does not satisfy the resonance condition, and thus the active layer ( The light along the etched region 60b among the light generated by 57 may pass through the second reflector layer 59 as it is. However, in the case where resonance does not occur in this manner, light is not amplified, ie, lasered in this region as a result, so that the overall surface light laser 50 efficiency is not significantly affected.

Therefore, when the lens 60 is integrally formed on the surface light laser 50 by etching a part of the second reflector layer 59 in a Fresnel pattern, the light output characteristic is shown in FIG. 6. While maintaining the same or similar to a general surface light laser 50 (the light emitted from the window is emitted), it is possible to focus the emitted laser light at a near focal position f, which, if employed, By positioning the recording medium at the focused position, near-field recording and reproduction can be realized with a structure in which an optical member such as a separate lens member and an optical path converting means is eliminated as described below. Here, in FIG. 6, the same reference numerals as used in FIGS. 3 and 5 denote members having substantially the same or similar functions.

In the above drawings, an example of the mesa structure in which the second reflector layer 59 protrudes is illustrated, but the basic structure of the surface light laser 50 may be variously modified.

Hereinafter, embodiments of the optical head for near field recording and reproducing employing the surface light laser according to the present invention will be described.

7 is a view schematically showing the configuration of an embodiment of an optical head for near field recording and reproducing employing a surface light laser according to the present invention. An optical head for near field recording and reproducing according to an embodiment of the present invention includes information on a recording medium 70 including a recording layer 71 and a transparent substrate 73 supporting the recording layer 71 and transmitting incident light. It is provided to record and reproduce.

Referring to the drawings, the optical head for near field recording and reproducing according to an embodiment of the present invention generates and emits laser light in the stacking direction of the semiconductor material layer, and the lens unit 60 provided in the form of a Fresnel pattern on the window side thereof is Light incident from the surface light laser 50 and the surface light laser 50 integrally provided on the recording layer 71 via the lens portion 60 and then transmitted through the transparent substrate 73. And a photodetector 80 mounted opposite to the surface light laser 50 to receive the light.

Here, the Fresnel pattern of the lens unit 60 is preferably provided so that the center of the pattern coincides with the center of the window 63, the configuration of the surface light laser 50 with reference to Figures 3 and / or 4 It is substantially the same as described.

The surface light laser 50 according to the present invention is provided in the slider 25 of the near field recording and reproducing apparatus as shown in FIG. The light emitted from the surface light laser 50 is diffracted by the lens unit 60 and focused at an adjacent focal position f.

When the recording medium 70 rotates, the surface light laser 50 floats against the recording medium 70 together with the slider 25 moving on the recording medium 70 while being floated by the pneumatic pressure generated by the rotation. The Fresnel pattern is designed such that the focal position f of the lens unit 60 is approximately positioned in the recording layer 71 upon such injury.

On the other hand, on the optical path between the surface light laser 50 and the recording medium 70, the light emitted from the surface light laser 50 is irradiated onto the recording medium 70 with little exposure to the air, It is preferable to further include a transparent member 90 to minimize the size, the transparent member 90 is installed integrally with the surface light laser 50 in close proximity to the window (63). Here, the transparent member 90 is preferably made of a high refractive member to focus more incident light.

This embodiment shows a case where the information is provided to record and reproduce the information of the recording medium 70 such as a phase change type optical disk by using light. In this case, a coil member (not shown) for magnetic field modulation is further provided between the slider 25 and the recording medium 70 or below the recording medium 70.

When the optical head is further provided with a coil member to record and reproduce the information of the recording medium 70 by optical and / or magnetic field modulation, the transparent substrate 73 and the photodetector 80 of the recording medium 70 are provided. Between the light receiving surface 80a, a pair of polarizing members (191, 195 of FIG. 9) for dividing light spots by approximately 2 and transmitting different polarization components are provided, and the function and structure of such polarizing members are different from those of other embodiments described below. same.

Such an optical head is a surface facing the recording medium 70 of the transparent member 90 when the slider 25 floats due to the rotation of the recording medium 70, in particular, a portion through which light passes and the recording medium 70. The air gap G therebetween becomes a close interval of about 20 to 300 nm to perform near field recording and reproducing.

Here, when the lens unit 60 is designed with a focal length such that the window 63 and the recording medium 70 of the surface light laser 50 directly face and perform near-field recording and reproduction, the transparent member (90) may be excluded.

8 is a diagram schematically showing a configuration of an optical head for near field recording and reproducing according to another embodiment of the present invention. Here, the same reference numerals as those of FIG. 7 denote members having substantially the same functions.

An optical head for near field recording and reproducing according to another embodiment of the present invention includes a recording medium including a recording layer 171 and a substrate 173 having a recording layer 171 supporting the recording layer 171 and reflecting incident light. 170) information can be recorded and reproduced.

That is, the optical head for near field recording and reproducing according to another embodiment of the present invention generates and emits laser light in the stacking direction of the semiconductor material layer, and the lens unit 160 provided in the form of a Fresnel pattern on the window 63 side is provided. In order to receive the light reflected from the reflective layer 173a which is integrally provided from the surface light laser 150 and the surface light laser 150 via the lens unit 160 and focused on the recording layer 171. It is configured to include a photodetector 180 installed on one side of the surface light laser 150.

FIG. 8 illustrates an embodiment in which the optical head is provided to record and reproduce information of a recording medium 170 such as a magneto-optical disc through optical and magnetic field modulation. The slider 25 is compared with the embodiment shown in FIG. And a coil member 120 for magnetic field modulation between the recording medium 170 or a lower portion of the recording medium 170. 8 shows an example in which a predetermined groove is formed on a surface of the transparent member 90 facing the recording medium 170 and the coil member 120 is mounted in the groove.

On the other hand, when the optical head is to record and reproduce the information of the recording medium 170 by light and / or magnetic field modulation as described above, the optical head is a light in front of the light receiving surface of the photodetector 180, as shown in FIG. It is further provided with a pair of polarizing members 191 and 195 for dividing the spot by approximately 2 and transmitting different polarization components. In addition, the photodetector 180 may include at least two split plates to receive incident light corresponding to the polarizing members 191 and 195 and to independently photoelectrically convert the light.

Here, the basic configuration of the surface light laser 150 is substantially the same as described with reference to FIGS. 3 and / or 4, and the Fresnel pattern has the center of the pattern as shown in FIG. 9. ) Is provided to be located out of a predetermined distance from the center.

When the Fresnel pattern is provided in this manner, the diffracted condensed light emitted from the surface light laser 150 is asymmetric in cross-sectional shape and intensity distribution of the beam, and at least some laser light is incident at an angle to the recording layer 171. Will be.

Accordingly, at least a portion of the light that is irradiated to the recording medium 170 by the surface light laser 150 and then reflected by the surface light laser 150 may be received by the photodetector 180 without a separate optical path converting means.

Meanwhile, as illustrated in FIG. 9, the pair of polarizing members 191 and 195 may be holographic gratings having a pattern direction perpendicular to each other and having a pattern interval smaller than an emission wavelength of the surface light laser 150. Do. The polarizing members 191 and 195 may be formed integrally with the photodetector 180 by forming a pattern by etching, for example, by laminating a transparent material layer on the light receiving surface of the photodetector 180.

The formation of the polarizing members 191 and 195 as described above uses the principle that the hologram grating functions as a polarizer by transmitting only the polarized light parallel to the longitudinal direction of the pattern when the pattern pitch is smaller than the incident light wavelength. The polarizing members 191 and 195 may be provided as separate members.

In this case, as shown in FIG. 9, the surface light laser 150, the photodetector 180, and the polarizing members 191 and 195 are electrically connected between the surface light laser 150 and the photodetector 180. The optical module 100 may be integrated into an insulated integrated structure.

On the other hand, when the optical head according to another embodiment of the present invention is provided to record and reproduce the information of the recording medium 170, such as a phase change type optical disk, the coil member 120 in FIG. As shown in FIG. 9, a configuration in which the pair of polarizing members 191 and 195 of FIG. 9 are omitted in the integrated structure of the surface light laser 150 and the photodetector 180 is sufficient.

Surface light as shown in FIGS. 9 and / or 10 employed in an optical head according to another embodiment of the present invention for recording and reproducing information of the recording medium 170 in a light reflection manner through light and / or magnetic field modulation. The integrated structure of the laser 150 and the photodetector 180 may be formed, for example, as shown in FIG. Here, since the structure of the surface light laser 150 is the same as in Figs. 3 to 4, the same reference numerals are used and the description thereof is omitted.

Referring to FIG. 11, the photodetector 180 shares a surface light laser 150 with a substrate 53 and a first electrode 51 formed on the bottom surface of the substrate 53. In addition, the photodetector 180 includes a detection electrode 188 formed in a predetermined pattern on at least a portion of the light receiving surface 180a except for the light receiving surface 180a. Here, the photodetector 180 and the surface light laser 150 are formed on the substrate 53 to form a trench 155 therebetween, or to be electrically insulated from each other in the lateral direction by ion implantation or the like. Herein, the trench 155 may be formed to a depth of a portion of the first reflector layer 55 of the surface light laser 150.

As the photodetector 180, an internal layer structure may be provided, for example, a PIN type photodetector consisting of first to third semiconductor material layers 185, 187, and 189 on the substrate 53. Can be. In this case, the first semiconductor material layer 185 preferably has substantially the same material composition and number of stacked layers as the first reflector layer 55 of the surface light laser 150. The second semiconductor material layer 187 is preferably made of the same material and thickness as the active layer 57 of the surface light laser 150. In addition, the third semiconductor material layer 189 has a material composition substantially the same as that of the second reflector layer 59 of the surface light laser 150, and has a smaller number of stacks than the second reflector layer 59. Preferably, light incident through the light receiving surface 180a is transmitted through the third semiconductor material layer 189 and absorbed by the second semiconductor material layer 187.

The photodetector 180 having such a structure may be integrally formed with the surface light laser 150 on the same semiconductor process. That is, the first reflector layer 55, the active layer 57, and the second reflector layer 59 are sequentially stacked on the substrate 53, and then the first reflector layer 55 is stacked between the surface light laser 150 and the photodetector 180. The trench 155 is formed to a part of the first reflector layer 55 to form electrical insulation in the lateral direction thereof, and only the number of stacked layers of the second reflector layer 59 in the region of the photodetector 180 is limited. You can leave it and etch it. On the light receiving surface 180a of the Fresnel pattern and / or photodetector 180 for forming the high resistance portion 58, the electrodes 51, 61, 188, the lens portion 160 through a subsequent process. A transparent material layer (not shown) is stacked on the substrate, and a pair of polarizing members 191 and 195 of FIG. 9 are formed by etching a predetermined pattern so that the pattern directions thereof are perpendicular to each other.

As described above, the optical head including the surface light laser 150 having the lens unit 160 in the Fresnel pattern according to the present invention and / or the optical module 100 in which the photodetector 180 is integrated therein Since converging light focused at a focal point proximate from the surface light laser 150 is emitted, the near field recording and reproducing can be performed in a structure that excludes separate optical elements such as the lens member and the optical path changing means.

The surface light laser according to the present invention as described above is a converged light in which the light emitted therefrom is focused at a position proximate from its window.

Therefore, the near-field recording and reproducing optical head employing this as a light source performs near-field recording and reproducing by mounting a surface light laser directly on the slider without an optical element such as a separate lens member, so the structure is simple and no separate optical alignment is necessary. In addition, it is possible to implement an ultra-miniature optical head for near field recording and reproduction.

Claims (14)

delete delete delete delete delete A near-field recording and reproducing optical head mounted on a slider moving on a recording medium while being floated by the air dynamic pressure generated by the rotation of the recording medium to record and reproduce information through optical and / or magnetic field modulation. The recording medium includes a recording layer and a transparent substrate supporting the recording layer and transmitting incident light, A substrate installed on the slider; A first electrode formed on the bottom surface of the substrate; A first reflector layer formed on the substrate; An active layer formed on the first reflector layer; A second reflector layer formed on the active layer; A second electrode formed on the second reflector layer; And a lens unit provided in the form of a Fresnel pattern on the side of the window so that the emitted laser light is focused at a position proximate to the diffraction focus. The laser unit generates and emits laser light in the stacking direction of the semiconductor material layer and is located close to the window. A surface light laser focusing on; And And a photodetector opposed to the surface light laser to receive light incident on the recording layer from the surface light laser via the lens portion and transmitted through the transparent substrate. head. A near-field recording and reproducing optical head mounted on a slider moving on a recording medium while being floated by the air dynamic pressure generated by the rotation of the recording medium to record and reproduce information through optical and / or magnetic field modulation. The recording medium comprises a substrate having a recording layer and a reflective layer supporting the recording layer and reflecting incident light, A substrate installed on the slider; A first electrode formed on the bottom surface of the substrate; A first reflector layer formed on the substrate; An active layer formed on the first reflector layer; A second reflector layer formed on the active layer; A second electrode formed on the second reflector layer; And a lens unit provided in the form of a Fresnel pattern on the side of the window so that the emitted laser light is focused at a position proximate to the diffraction focus. The laser unit generates and emits laser light in the stacking direction of the semiconductor material layer and is located close to the window. A surface light laser focusing on; And And a photodetector disposed at one side of the surface light laser to receive light focused from the surface light laser on the recording layer via the lens portion and reflected from the reflection layer. The Fresnel pattern of the lens unit is provided such that the center of the pattern is located a predetermined distance away from the center of the window so that at least some laser light is incident on the recording layer at an oblique angle and then reflected from the reflective layer to face the photodetector. An optical head for near field recording and reproducing, characterized by the above-mentioned. The optical head of claim 6 or 7, wherein the lens unit is formed by etching a portion of the second reflector layer in the form of a Fresnel pattern. 8. A recording apparatus according to claim 6 or 7, further comprising a coil member between the slider and the recording medium and / or under the recording medium to record and reproduce signals by optical and magnetic field modulation. And a pair of polarizing members for dividing the incident light spot by approximately two on the light receiving surface of the photodetector to transmit different polarization components. The method of claim 9, wherein the pair of polarizing members, An optical head for near field recording and reproducing, characterized in that the pattern direction is a hologram grating formed at right angles to each other and whose pattern interval is smaller than the emission wavelength of the surface light laser. The method of claim 10, wherein the pair of polarizing members, And a transparent material layer having patterns orthogonal to each other on the light receiving surface of the photodetector. The method of claim 7, wherein the photodetector, Sharing a substrate of the surface light laser and a first electrode formed on the bottom surface of the substrate, And a detection electrode having a predetermined pattern on at least a portion of the substrate except for the light receiving surface. The method of claim 12, wherein the photodetector, A first semiconductor material layer having substantially the same material composition and number of stacked layers as the first reflector layer, the first semiconductor material layer being at least partially spaced apart from the surface light laser by a predetermined distance; A second semiconductor material layer formed on the first semiconductor material layer and made of substantially the same material and thickness as the active layer; And a third semiconductor material layer formed on the second semiconductor material layer and having a material configuration substantially the same as that of the second reflector layer, and having a smaller number of stacks than the second reflector layer. An optical head for near field recording and reproducing, wherein the surface light laser and the photodetector can be integrally formed in the same semiconductor manufacturing process. The optical head for near field recording and reproduction according to claim 13, wherein the electrical insulation in the lateral direction between the surface light laser and the photodetector is formed by forming a trench therebetween or by ion implantation.

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