JP2006120295A - Solid immersion lens, condensing lens using the same, optical pickup device, magneto-optical recording / reproducing device, and method for forming solid immersion lens - Google Patents

Abstract

A solid immersion lens capable of ensuring a tilt margin with respect to a magneto-optical recording medium and maintaining good magnetic field generation efficiency by a magnetic coil, a condensing lens using the same, an optical pickup device, and magneto-optical A recording / reproducing apparatus is provided.
A convex portion 2 is formed on the objective side of a solid immersion lens 11 and an objective surface 3 is provided at the tip of the convex portion 2. The magnetic recording magnetic coil 9 is embedded.
[Selection] Figure 8

Description

  The present invention relates to a solid immersion lens, a condensing lens using the same, an optical pickup device, a magneto-optical recording / reproducing device, and a method for forming a solid immersion lens. More specifically, the present invention relates to a lens material having a large refractive index and a large numerical aperture. A solid immersion lens that realizes a near-field magneto-optical recording / reproducing system by performing at least magneto-optical recording using the condensing lens, and a condensing lens, an optical pickup device, a magneto-optical recording / reproducing device, and a solid using the same The present invention relates to a method for forming an immersion lens.

Optical recording media (including magneto-optical recording media) represented by compact disc (CD), mini disc (MD), and digital versatile disc (DVD) are used as storage media for music information, video information, data, programs, and the like. Widely used. However, for higher sound quality, higher image quality, longer time, and larger capacity of music information, video information, data, programs, etc., a larger capacity optical recording medium and optical recording / reproducing for recording / reproducing the same An apparatus (including a magneto-optical recording / reproducing apparatus) is desired.
Therefore, in order to cope with these, in the optical recording / reproducing apparatus, the wavelength of the light source, for example, the semiconductor laser is shortened, the numerical aperture of the condensing lens is increased, and the light spot converged through the condensing lens is reduced. The diameter has been reduced.

  For example, with regard to semiconductor lasers, GaN semiconductor lasers whose oscillation wavelength has been shortened from the 635 nm to 400 nm bands of conventional red lasers have been put into practical use, and thereby the diameter of the light spot is being reduced. For further shortening of the wavelength, for example, a far ultraviolet solid-state laser UW-1020A (trade name) manufactured by Sony Corporation that continuously oscillates light having a single wavelength of 266 nm has been put on the market. Spot diameters are also being reduced. In addition to this, research and development of a Nd: YAG laser double wave laser (266 nm band), a diamond laser (235 nm band), a GaN laser double wave laser (202 nm band), and the like are underway.

  Further, by using an optical lens having a large numerical aperture represented by a solid immersion lens (SIL), for example, a condensing lens having a numerical aperture of 1 or more is realized, and the objective surface of the condensing lens is used as an optical recording medium. Then, a so-called near-field optical recording / reproducing system in which recording / reproducing is performed by bringing the light source wavelength close to about one-tenth of the light source wavelength has been studied (for example, see Patent Document 1).

  In this near-field optical recording / reproducing system, it is important to maintain the distance between the optical recording medium and the condenser lens in an optical contact state with high accuracy. In addition, the diameter of the light beam emitted from the light source and incident on the condensing lens becomes small, and the distance between the optical recording medium and the condensing lens is very small, about tens of nm or less. The tilt margin with the lens, the so-called tilt margin, becomes very small, and the condensing lens is greatly restricted in shape.

  FIG. 15 shows a schematic configuration diagram of an example of a solid immersion lens. The solid immersion lens 11 and the optical lens 12 can be arranged in order from the objective side facing the optical recording medium, in the illustrated example, the magneto-optical recording medium 10 to form a near-field condensing lens. As shown in FIG. 15, the solid immersion lens 11 is formed in a hemispherical shape or a super hemispherical shape (super hemispherical in the illustrated example) with a radius of curvature r. r, in the case of a super hemisphere as in the illustrated example, if the refractive index is n, the thickness along the optical axis is configured as r (1 + 1 / n).

When the condensing lens having such a configuration is applied to an optical recording / reproducing apparatus, for example, it is mounted on an optical pickup apparatus having a biaxial actuator, and the distance between the optical recording medium and the condensing lens is maintained in an optical contact state. To do. When used for magneto-optical recording, a magnetic head device used for magneto-optical recording and reproduction is incorporated in the optical pickup device, and the distance between the magneto-optical recording medium and the condenser lens is similarly maintained in an optical contact state. It is supposed to be configured.
Japanese Laid-Open Patent Publication No. 5-189796

  In the above-mentioned near-field magneto-optical recording / reproducing system, in order to perform stable control of the condenser lens controlled and driven in the focusing direction and / or the tracking direction with respect to the magneto-optical recording medium, and to perform stable recording / reproduction with the magneto-optical recording medium. In addition, it is necessary to secure a certain degree of inclination margin between the objective surface of the magneto-optical recording medium and its condenser lens.

  However, when a magnetic coil is formed on the objective surface in a super-hemispherical solid immersion lens having a flat objective surface as shown in FIG. 15, the margin of inclination of the objective surface with respect to the magneto-optical recording medium is formed. Is extremely small and it is difficult to perform stable recording and reproduction. In addition, since the area of the objective surface of the lens having the magnetic coil is large, dust easily enters the gap between the magneto-optical recording medium and the solid immersion lens, and the solid immersion lens and the magneto-optical recording medium easily collide. There is a problem.

  On the other hand, the applicant of the present application (Japanese Patent Application No. 2005-34884 that claimed priority based on Japanese Patent Application No. 2004-73161) and Japanese Patent Application No. 2005 that claimed priority based on Japanese Patent Application No. 2004-73162. In the application of No. 18862), on the object side of the solid immersion lens, for example, a convex part that is inclined or curved toward the light condensing part such as a conical shape, a pyramid shape, or a curved surface shape is provided, and the tip portion is processed into a flat shape. By adopting an objective surface, we proposed a solid immersion lens that was processed so that an inclination margin of about ± 0.1 degrees or more could be secured even when the distance between the objective surface and the optical recording medium was several tens of nanometers. . Thereby, it is possible to provide an optical pickup device and an optical recording / reproducing device capable of stabilizing the recording / reproducing characteristics.

  Thus, when performing magneto-optical recording / reproduction using a solid immersion lens having a convex object surface, if the tip of the lens is conical, for example, and a magnetic coil is formed on the conical slope, a certain degree of tilt margin is provided. It can be secured. However, when the magnetic coil is provided on the inclined surface in this manner, the magnetic field generated by the magnetic coil is efficiently applied to the magneto-optical recording medium because the distance from the magneto-optical recording medium becomes large at a position away from the optical axis. There is a risk that it will not be possible.

  In view of such problems, the present invention is applied to a near-field magneto-optical recording / reproducing system capable of ensuring a tilt margin with respect to a magneto-optical recording medium and maintaining good magnetic field generation efficiency by a magnetic coil. In addition to providing a suitable solid immersion lens, a condensing lens using the same and an optical pickup device are provided, and a magneto-optical recording / reproducing apparatus corresponding to high density and large capacity of a magneto-optical recording medium is provided. Objective.

In order to solve the above-described problems, the present invention comprises a convex portion formed on the objective side of a solid immersion lens, and an objective surface provided at the tip of the convex portion. The magnetic coil for magneto-optical recording is embedded.
The condensing lens, the optical pickup device, and the optical recording / reproducing device according to the present invention are configured to use the solid immersion lens of the above-described configuration of the present invention.
That is, the present invention relates to a condensing lens constituted by an optical lens that is aligned with an optical axis of a solid immersion lens and is disposed on the side opposite to the objective side, wherein the solid immersion lens has a convex portion on the objective side. Is formed, and an objective surface is provided at the tip of the convex portion, and a magnetic coil for magneto-optical recording is embedded in the periphery of the condensing portion of the objective surface.

Furthermore, the present invention provides an optical pickup apparatus having at least a magnetic head for magneto-optical recording that performs recording by condensing light at a recording position of a magneto-optical recording medium by a condensing lens, As the objective lens, a solid immersion lens is used. This solid immersion lens has a convex portion formed on the objective side and an objective surface provided at the tip of the convex portion. A magnetic coil for magneto-optical recording is embedded in the periphery of the optical portion.
The present invention also includes an optical pickup device having at least a magnetic head for magneto-optical recording for condensing light at a recording position of a magneto-optical recording medium by a condensing lens, In the magneto-optical recording / reproducing apparatus provided with at least control driving means for controlling and driving the optical pickup device in the focusing direction and / or the tracking direction of the magneto-optical recording medium, at least the objective lens of the condenser lens A solid immersion lens is used, and this solid immersion lens has a convex portion formed on the objective side and an objective surface provided at the tip of the convex portion. A magnetic coil for magneto-optical recording is embedded.

  Furthermore, the present invention is a method of forming a solid immersion lens, wherein a concave portion is formed by focus ion beam etching at least on the periphery of the condensing portion of the objective surface of the solid immersion lens. A magnetic coil for magneto-optical recording is embedded.

  In the solid immersion lens of the present invention described above, a convex portion is provided on the objective side, and a concave portion is provided on a part of the objective surface so that the magnetic coil is embedded. The distance from the information recording surface of the magnetic recording medium can be made substantially constant, and variations and decreases in the magnetic field application efficiency are suppressed.

As described above, according to the solid immersion lens and the condensing lens of the present invention, since the convex portion is provided on the objective side, an inclination margin with the magneto-optical recording medium is secured and a part of the objective surface is provided. By embedding the magnetic coil in the magnetic field, it is possible to suppress a decrease in the efficiency of applying the magnetic field to the magneto-optical recording medium.
Furthermore, according to the optical pickup device and the optical recording / reproducing apparatus of the present invention, it is possible to secure a tilt margin between the condenser lens and the magneto-optical recording medium and to maintain a good magnetic field application efficiency to the magneto-optical recording medium. Thus, stable magneto-optical recording / reproduction is possible.
In addition, according to the method of forming a solid immersion lens of the present invention, a concave portion for embedding a magnetic coil can be formed with high accuracy, and a solid immersion lens that suppresses a decrease in magnetic field application efficiency to a magneto-optical recording medium can be stably produced. Can be provided.

Examples of the best mode for carrying out the present invention will be described below, but the present invention is not limited to the following examples.
The present invention has a condensing lens composed of a solid immersion lens, an optical lens that is aligned with the optical axis of the solid immersion lens and disposed on the side opposite to the objective side, and further includes the condensing lens. The present invention can be applied to an optical pickup apparatus that employs a so-called near-field magneto-optical recording / reproducing system and a magneto-optical recording / reproducing apparatus having the optical pickup apparatus.

  First, prior to the description of the solid immersion lens according to the present invention, an example of an embodiment applied to the condenser lens, the optical pickup device, and the magneto-optical recording / reproducing device will be described with reference to FIGS. In FIG. 1 to FIG. 3, the shape of the solid immersion lens is shown by simplifying an example according to the configuration of the present invention in order to easily explain the arrangement configuration. Various shapes including the example shown in FIG. 7 can be taken.

FIG. 1 is a schematic configuration diagram showing an example of a condensing lens using a solid immersion lens according to the present invention. A solid immersion lens 11 and an optical lens 12 according to the configuration of the present invention are arranged so that their optical axes are aligned in this order, facing a lens object such as a magneto-optical recording medium 10. The solid immersion lens 11 is hemispherical or super hemispherical with a radius of curvature r. The thickness along the optical axis is r when hemispherical, and r when the refractive index is n when super hemispherical. (1 + 1 / n). With such a configuration, it is possible to provide a condensing lens 13 having a high numerical aperture exceeding the numerical aperture NA of the optical lens 12.
The solid immersion lens 11 of the present invention has a configuration in which a magnetic coil 9 is embedded in a part of the objective surface 3 thereof. The terminal of the magnetic coil 9 embedded in the objective surface 3 is connected to a magnetic field generating circuit (not shown), and a recording magnetic field or a reproducing magnetic field is generated by supplying an alternating current or a direct current during recording and / or reproduction. Is generated.
Actually, the solid immersion lens 11 and the magneto-optical recording medium 10 are not in contact with each other, but the distance between the solid immersion lens 11 and the magneto-optical recording medium 10 is sufficiently larger than the thickness of the solid immersion lens 11. Therefore, the interval is not shown in FIGS.

  FIG. 2 is a schematic configuration diagram showing an example of the configuration of the optical system of the optical pickup device using the solid immersion lens and the condenser lens shown in FIG. For example, first and second beam splitters 14 and 15 are arranged between a light source and a photodetector (not shown) and a condenser lens 13 including a solid immersion lens 11 and an optical lens 12. If the magneto-optical recording medium 10 is in the form of a disk, for example, it is mounted on a spindle motor (not shown) and rotated at a predetermined rotational speed.

The optical pickup device shown in FIGS. 1 and 2 is provided with means for controlling and driving the condenser lens 13 in the tracking direction and the focusing direction.
Examples of this means include a biaxial actuator used for a general optical pickup and a slider used for a magnetic head device.
The form of the control drive means of these condensing lenses 13 is shown below.

FIG. 3 is an example of an optical pickup device constituting a part of the magneto-optical recording / reproducing apparatus of the present invention, and shows a schematic configuration diagram of an example using a biaxial actuator as a control driving means. As shown in FIG. 3, the condenser lens 13 is fixed by a holding body 20 so that the optical axes of the solid immersion lens 11 and the optical lens 12 coincide with each other, and the holding body 20 is controlled in the focusing direction and / or the tracking direction. It is fixed to a driven biaxial actuator 16.
As shown in FIG. 3, the biaxial actuator 16 includes a tracking coil 17 for controlling and driving the condenser lens 13 in the tracking direction, and a focusing coil 18 for controlling and driving the focusing lens 13 in the focusing direction.

The biaxial actuator 16 allows the distance between the magneto-optical recording medium 10 and the solid immersion lens 11 to be controlled, for example, by monitoring the amount of return light and feeding back the distance information. The distance from the medium 10 is kept substantially constant, and the solid immersion lens 11 and the magneto-optical recording medium 10 are controlled to avoid collision.
Further, in this biaxial actuator 16, it is possible to move the focused spot to a desired recording track by monitoring the amount of light returning in the tracking direction and feeding back the position information.

  Hereinafter, a schematic configuration of the optical pickup device will be described with reference to FIG. 2 again. Outgoing light emitted from a light source, for example, a semiconductor laser, is converted into parallel light by a collimator lens (not shown) (L1), passes through the first beam splitter 14, and passes through the condenser lens 13 as indicated by an arrow Li. Then, the light is condensed on the information recording surface of the magneto-optical recording medium 10. The return light reflected by the information recording surface passes through the condenser lens 13, is reflected by the first beam splitter 14 (L 2), and enters the second beam splitter 15. The return light beams (L3 and L4) separated by the second beam splitter 15 are condensed on a focusing photodetector and a signal photodetector (not shown), and a focusing error signal and a reproduced pit signal are collected. Etc. are detected.

  Further, the return light reflected by the second beam splitter is condensed, for example, on a tracking photodetector, and a tracking error signal is detected. If necessary, the optical pickup device includes a focus error component left by the biaxial actuator that fixes the condenser lens 13 to the surface shake of the magneto-optical recording medium 10 and a process for assembling the condenser lens. A relay lens that can correct an error component that sometimes occurs by changing the interval between the two lenses may be inserted between the first beam splitter 14 and the optical lens 12.

Although not shown, when the condenser lens is mounted on the slider, the condenser lens is fixed to the slider as a means to correct the remaining focus error component that the slider followed and the error component generated during the condenser lens assembly process. The optical lens may be configured to be movable in the optical axis direction by, for example, a piezoelectric element.
In the case of a magneto-optical recording / reproducing apparatus in which the spindle motor has means for mounting a plurality of magneto-optical recording media, it is preferable that the slider be provided with a mirror that bends the optical axis approximately 90 degrees. In the magneto-optical recording / reproducing apparatus having such a configuration, the interval between the magneto-optical recording media can be reduced, and as a result, the apparatus can be reduced in size and thickness.

  The above-described optical pickup device includes a read-only unit that performs only magneto-optical recording reproduction, a recording-only unit that performs only magneto-optical recording, and a recording / reproducing unit that can perform both recording and reproduction. The magneto-optical recording / reproducing apparatus includes a reproduction-only apparatus that performs only reproduction of magneto-optical recording, a recording-only apparatus that performs only magneto-optical recording, and a recording / reproducing apparatus that can perform both recording and reproduction.

Next, an example of a lens shape suitable for application to the solid immersion lens of the present invention will be described.
4A and 4B are a schematic side view and a schematic plan view of an example of a solid immersion lens according to the present invention. In this case, the spherical portion 1 is a super hemispherical shape, and the radius of curvature of the spherical portion 1 is r, the refractive index is n, and the thickness along the optical axis c is r (1 + 1 / n). On the object side, a convex portion 2 protruding toward the object surface 3 is provided, and the magnetic coil 9 is embedded in at least a part of the object surface 3.
In FIG. 4, a broken line R indicates a cross section having a radius r in a cross section orthogonal to the optical axis of the solid immersion lens 11.
In the solid immersion lens 11 of the present invention, the shape of the convex portion 2 may be a conical shape or a pyramid shape.
Further, as shown in FIGS. 5A and 5B, the spherical portion 1 is hemispherical, the thickness along the optical axis is r, and the convex portion 2 is substantially conical or pyramid-shaped, and the objective surface 3 at the tip portion. The shape may be substantially circumscribed by a sphere indicated by a broken line f having a radius of about r / 2. In this case, even when the optical axis of incident light such as a laser is slightly tilted from the optical axis of the lens 11, the distance through which the incident light passes through the solid immersion lens 11 does not change, and the objective is satisfactorily achieved. It has the advantage that it can be focused on the surface.

Further, for example, as shown in FIGS. 6A and 6B, the spherical portion 1 has a super hemispherical shape, the convex portion 2 has a substantially conical shape or a pyramid shape, and the objective surface 3 at the tip portion has a radius of approximately r / n. It is good also as a shape substantially circumscribed on the sphere shown with the dashed-dotted line g. Also in this case, even when the optical axis of incident light such as a laser is slightly tilted from the optical axis of the lens 11, the distance through which the incident light passes through the solid immersion lens 11 does not change, and the objective is satisfactorily achieved. It has the advantage that it can be focused on the surface.
Furthermore, as shown to FIG. 7A and B, the convex-shaped part 2 can also be made into the various curved surface shape containing a spherical surface, for example.
In FIGS. 5A and B, FIGS. 6A and B, and FIGS. 7A and B, parts corresponding to those in FIGS.

  Note that the inclination angle of the convex portion 2 is set to be larger than the incident angle so as not to disturb the incident light of the laser. For example, when a lens material having a refractive index of about 2 to 3 is used, the inclination angle is the light angle. It is about 60 to 80 degrees from the axis.

As described above, the material of such a solid immersion lens has a large refractive index, large transmittance, and light absorption with respect to the wavelength of the laser light source equipped in the magneto-optical recording / reproducing apparatus and optical pickup apparatus used. A material having a small is suitable as a material. For example, S-LAH79 (trade name) manufactured by OHARA INC. Which is a high refractive index glass, Bi ₄ Ge ₃ O ₁₂ , SrTiO ₃ , ZrO ₂ , which is a high refractive index ceramic, a high refractive index single crystal material, HfO ₂ , SiC, KTaO ₃ , diamond and the like are suitable.

  Further, it is desirable that these lens materials have an amorphous structure or a cubic structure in the case of a single crystal. In the case where the lens material has an amorphous structure or a cubic structure, the etching rate and etching characteristics do not change depending on the crystal orientation, so that it is possible to use a known etching method or apparatus used for processing a semiconductor or the like.

Further, in the solid immersion lens 11 of the present invention, for the processing of the recess that is the embedded portion of the magnetic coil 9 in the objective surface 3, a known etching method or apparatus used for semiconductor processing can be used. In particular, for processing a fine tip, it is preferable to use a focused ion beam processing method and processing apparatus such as a focused ion beam processing observation apparatus FB-2100 (trade name) manufactured by Hitachi, Ltd. is there.
By forming the concave portion by such a focused ion beam processing method, the shape such as the depth of the concave portion and the arrangement position thereof can be formed with high accuracy, and the influence on incident light incident on the solid immersion lens can be affected. It is possible to avoid and stably provide the solid immersion lens of the configuration of the present invention.

FIG. 8 shows a schematic sectional configuration diagram of an example of the solid immersion lens 11 according to the present invention. As shown in FIG. 8, for example, a magneto-optical recording magnetic coil 9 is embedded in a part of the objective surface 3 facing the magneto-optical recording medium 10 at the tip of a convex portion having a conical shape or a pyramidal shape. To do. In this case, the distance d between the magnetic coil 9 and the magneto-optical recording medium 10 is substantially constant at any position.
FIG. 9 shows a schematic cross-sectional configuration in which the main part of such a solid immersion lens 11 is enlarged. On the objective surface 3 which is a flat surface facing the magneto-optical recording medium, a concave portion 5 is formed around the condensing portion 4 where incident light is condensed as indicated by a broken line arrow Li, and a magnetic coil is formed inside the concave portion 5. 9 is embedded.
In addition, as a shape of the recessed part 5, for example, the plane can be a closed loop shape such as a ring shape or a square shape, and the cross section can be a variety of shapes such as a square shape, a U shape, or a V shape.
Further, the depth and shape of the recess 5 are selected so as not to block the incident angle of incident light such as a laser beam on the solid immersion lens 11.
Further, the inclination angle of the objective surface 3 and the convex portion 2 of the solid immersion lens, or the configuration such as the curvature when the convex portion is curved so that the inclination margin with the magneto-optical recording medium 10 is maximized. It is desirable to process and form.
By adopting such a configuration, it is possible to secure a sufficient inclination margin with respect to the magneto-optical recording medium 10 and to suppress variation and decrease in the magnetic field application efficiency of the magnetic coil.

  On the other hand, as shown in a schematic configuration in FIG. 10 as a comparative example, the solid immersion lens 11 is, for example, a super hemisphere, and a cylindrical convex portion is provided only in the vicinity of the focusing portion on the objective side, and the periphery thereof is flat. When the magnetic coil 9 is formed on the flat surface 7 configured as the surface 7, the area of the flat surface 7 becomes relatively large, and the tilt margin with the magneto-optical recording medium 10 cannot be made sufficiently small.

As another comparative example, as shown in a schematic configuration in FIG. 11, when the convex portion 2 such as a conical shape is provided on the object side of the solid immersion lens 11 and the magnetic coil 9 is provided on the inclined surface 8, As described above, the position d of the magnetic coil 9 away from the optical axis c, that is, the distance d from the magneto-optical recording medium 10 on the outer peripheral side becomes larger than the central side (optical axis c side). The magnetic field application efficiency is lowered at the portion.
It can be seen that these disadvantages can be avoided in the solid immersion lens according to the present invention.

  Next, an example of a solid immersion lens having the configuration of the present invention will be described. In this example, a conical convex portion is provided on the objective side of the solid immersion lens, and a flat ring-shaped concave portion is provided around the condensing portion on the flat objective surface at the tip thereof to embed the magnetic coil. The configuration.

As a material of the solid immersion lens, a high refractive index glass material of S-LAH79 (trade name) manufactured by Ohara Co., Ltd. is used, the radius of the solid immersion lens is 0.45 mm, and the thickness thereof is 0.667 mm. A solid immersion lens was produced by making the convex portion of the objective surface into a conical shape having an angle from the optical axis of about 70 degrees.
In this solid immersion lens, as shown in a schematic plan view in FIG. 12, a magnetic coil 9 was formed around the condensing part 4 at the center position of the objective surface 3 by application of photolithography. Although not shown, the magnetic coil terminal 9a is connected to an external magnetic field generating circuit, and generates a recording magnetic field or a reproducing magnetic field by flowing an alternating current or a direct current during recording and / or reproducing. To do.

FIG. 13 shows a schematic configuration of the recess 5 in which the magnetic coil 9 is embedded. In this example, on the object plane 3, a concave portion 5 having a planar ring shape having a diameter d1 of the light collecting portion 4 at the central position of 10 μm, an outer diameter d2 of 50 μm, and a depth d3 of 5 μm, and a substantially square cross section is provided. It was formed with a focus ion beam processing apparatus. In this example, the processing time of the recess 5 was 13 minutes.
The observation photograph figure in the state which formed this recessed part 5 is shown in FIG. From FIG. 14, it can be confirmed that the ring-shaped recess shape for embedding the magnetic coil can be processed with high accuracy.
Furthermore, it was confirmed that the influence of the concave portion on the incident light can be avoided by adjusting the incident angle of incident light such as a laser.

  In the solid immersion lens having such a configuration, when the distance between the surface of the magneto-optical recording medium and the objective surface is 50 nm, the inclination margin with respect to the magneto-optical recording medium is ± 0.10 degrees.

As described above, according to the present invention, a solid immersion lens having a large tilt margin between the objective surface of the lens and the optical recording medium and a high magnetic field application efficiency can be realized. Thus, a condensing lens having a large numerical aperture can be easily obtained. In the optical pickup device and the magneto-optical recording / reproducing apparatus configured using the condenser lens, the performance of the condenser lens controlled and driven in the focusing direction and / or the tracking direction of the magneto-optical recording medium is enhanced, that is, In addition to ensuring a tilt margin, stable control can be achieved, and the magneto-optical recording / reproducing characteristics can be satisfactorily maintained.
Therefore, it is possible to provide a practical optical pickup device and a magneto-optical recording / reproducing apparatus corresponding to a magneto-optical recording medium that employs a near-field recording / reproducing method to achieve high density and large capacity.

  The present invention is not limited to the materials and configurations described in the above examples. For example, as the shape of the convex portion of the solid immersion lens, a shape having a step due to a combination of a convex curved surface and a concave curved surface is used. Needless to say, the arrangement and configuration of the magnetic coil, and the configuration of the optical pickup device and the magneto-optical recording / reproducing device can be variously modified and changed without departing from the configuration of the present invention. .

It is a schematic block diagram of an example of the condensing lens by this invention. It is a schematic block diagram of the principal part of an example of the optical pick-up apparatus by this invention. It is a schematic block diagram of the principal part of an example of the optical recording / reproducing apparatus by this invention. A is a schematic side view of an example of a solid immersion lens applicable to the present invention. B is a schematic plan view of an example of a solid immersion lens applicable to the present invention. A is a schematic side view of an example of a solid immersion lens applicable to the present invention. B is a schematic plan view of an example of a solid immersion lens applicable to the present invention. A is a schematic side view of an example of a solid immersion lens applicable to the present invention. B is a schematic plan view of an example of a solid immersion lens applicable to the present invention. A is a schematic side view of an example of a solid immersion lens applicable to the present invention. B is a schematic plan view of an example of a solid immersion lens applicable to the present invention. It is a schematic block diagram of an example of the solid immersion lens by this invention. It is a schematic block diagram of the principal part of an example of the solid immersion lens by this invention. It is a schematic block diagram of an example of the solid immersion lens by a comparative example. It is a schematic block diagram of an example of the solid immersion lens by a comparative example. It is a schematic plane block diagram of the principal part of an example of the solid immersion lens by this invention. It is a schematic sectional block diagram of the principal part of an example of the solid immersion lens by this invention. It is an observation photograph figure of the principal part of an example of the solid immersion lens by the present invention. It is a schematic block diagram of an example of the condensing lens using the conventional solid immersion lens.

Explanation of symbols

  1. 1. spherical part; 2. convex portion; Object plane, 5. Recess, 7. Flat surface, 8. Slopes, 9. Magnetic coil, 10. 10. magneto-optical recording medium; Solid immersion lens, 12. Optical lens, 13. Condensing lens, 14. First beam splitter, 15. 16. second beam splitter, 16.2 axis actuator, Tracking coil, 18. Coil for focusing, 20. Holding body

Claims (6)

A convex part is formed on the objective side of the solid immersion lens, and an objective surface is provided at the tip of the convex part.
A solid immersion lens, wherein a magnetic coil for magneto-optical recording is embedded in the periphery of the condensing portion of the objective surface. 2. The solid immersion lens according to claim 1, wherein the convex portion has a conical shape, a pyramid shape, or a curved surface shape. In a condensing lens composed of a solid immersion lens and an optical lens that is aligned with the optical axis of the solid immersion lens and opposite to the objective side,
The solid immersion lens has a convex portion formed on the objective side, and an objective surface is provided at the tip of the convex portion.
A condensing lens, wherein a magnetic coil for magneto-optical recording is embedded around the condensing portion of the objective surface. In an optical pickup device including at least a magnetic head for magneto-optical recording that performs recording by condensing light at a recording position of a magneto-optical recording medium by a condensing lens,
A solid immersion lens is used as at least the objective lens among the condenser lenses,
The solid immersion lens has a convex portion formed on the objective side, and an objective surface is provided at the tip of the convex portion.
An optical pickup device, wherein a magnetic coil for magneto-optical recording is embedded in the periphery of the light converging portion of the objective surface. An optical pickup device including at least a magnetic head for magneto-optical recording that performs recording by condensing light at a recording position of a magneto-optical recording medium by a condensing lens, and the condensing lens and the optical pickup device are In a magneto-optical recording / reproducing apparatus comprising at least control drive means for controlling and driving in a focusing direction and / or a tracking direction of a magneto-optical recording medium,
A solid immersion lens is used as at least the objective lens among the condenser lenses,
The solid immersion lens has a convex portion formed on the objective side, and an objective surface is provided at the tip of the convex portion.
A magneto-optical recording / reproducing apparatus, wherein a magnetic coil for magneto-optical recording is embedded in the periphery of the light converging portion of the objective surface. A method of forming a solid immersion lens,
A concave portion is formed by a focus ion beam etching method on at least a portion of the objective surface of the solid immersion lens at the periphery of the light collecting portion.
A method of forming a solid immersion lens, comprising embedding a magnetic coil for magneto-optical recording in the recess.