WO2010100994A1 - Élément optique et tête d'enregistrement optique - Google Patents

Élément optique et tête d'enregistrement optique Download PDF

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Publication number
WO2010100994A1
WO2010100994A1 PCT/JP2010/051602 JP2010051602W WO2010100994A1 WO 2010100994 A1 WO2010100994 A1 WO 2010100994A1 JP 2010051602 W JP2010051602 W JP 2010051602W WO 2010100994 A1 WO2010100994 A1 WO 2010100994A1
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WIPO (PCT)
Prior art keywords
light
optical element
light source
optical
eccentricity
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PCT/JP2010/051602
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English (en)
Japanese (ja)
Inventor
真奈美 杭迫
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コニカミノルタオプト株式会社
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Priority to JP2011502695A priority Critical patent/JPWO2010100994A1/ja
Publication of WO2010100994A1 publication Critical patent/WO2010100994A1/fr

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    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/127—Structure or manufacture of heads, e.g. inductive
    • G11B5/31—Structure or manufacture of heads, e.g. inductive using thin films
    • G11B5/3109—Details
    • G11B5/313—Disposition of layers
    • G11B5/3133—Disposition of layers including layers not usually being a part of the electromagnetic transducer structure and providing additional features, e.g. for improving heat radiation, reduction of power dissipation, adaptations for measurement or indication of gap depth or other properties of the structure
    • G11B5/314—Disposition of layers including layers not usually being a part of the electromagnetic transducer structure and providing additional features, e.g. for improving heat radiation, reduction of power dissipation, adaptations for measurement or indication of gap depth or other properties of the structure where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B5/48—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed
    • G11B5/4806—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives
    • G11B5/4866—Disposition or mounting of heads or head supports relative to record carriers ; arrangements of heads, e.g. for scanning the record carrier to increase the relative speed specially adapted for disk drive assemblies, e.g. assembly prior to operation, hard or flexible disk drives the arm comprising an optical waveguide, e.g. for thermally-assisted recording
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/122—Flying-type heads, e.g. analogous to Winchester type in magnetic recording
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1362—Mirrors
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B7/00—Recording or reproducing by optical means, e.g. recording using a thermal beam of optical radiation by modifying optical properties or the physical structure, reproducing using an optical beam at lower power by sensing optical properties; Record carriers therefor
    • G11B7/12—Heads, e.g. forming of the optical beam spot or modulation of the optical beam
    • G11B7/135—Means for guiding the beam from the source to the record carrier or from the record carrier to the detector
    • G11B7/1372—Lenses
    • G11B7/1378—Separate aberration correction lenses; Cylindrical lenses to generate astigmatism; Beam expanders
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B2005/0002—Special dispositions or recording techniques
    • G11B2005/0005—Arrangements, methods or circuits
    • G11B2005/001—Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure
    • G—PHYSICS
    • G11—INFORMATION STORAGE
    • G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
    • G11B5/00—Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor
    • G11B2005/0002—Special dispositions or recording techniques
    • G11B2005/0005—Arrangements, methods or circuits
    • G11B2005/0021—Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal

Definitions

  • the present invention relates to an optical element and an optical recording head.
  • the heat-assisted magnetic recording method is one of them.
  • the magnetic recording method it is necessary to reduce the size of each magnetic domain in order to increase the density, but in order to stably store data, an information recording medium made of a material having a large coercive force is used. There must be.
  • an information recording medium it is necessary to generate a strong magnetic field when writing, but there is a limit to the strength of the magnetic field in a small head corresponding to a reduced magnetic domain.
  • the heat-assisted magnetic recording method is a method that facilitates writing by lowering the coercive force by heat.
  • the optically assisted magnetic recording method uses light as a heating means and is similar to recording on a magneto-optical disk (MO).
  • MO magneto-optical disk
  • each data section is much smaller in optically assisted magnetic recording, and it is necessary to apply a magnetic field while heating the medium with light, so it is necessary to bring the heating optical part closer to the magnetic recording part. is there.
  • the optical recording head that can be used for the optically assisted magnetic recording head needs to be much smaller than the recording head corresponding to the MO.
  • the optical recording head described in Patent Document 1 includes a reflecting surface that has a part of a rotating paraboloid in order to collect light, and the optical recording head described in Patent Document 2 collects light.
  • a small-sized optical recording head which includes a reflecting surface having a part of a spheroid surface and deflects the light beam at the same time and collects the light simultaneously.
  • the paraboloidal reflecting surface described in Patent Document 1 needs to introduce parallel light in order to collect the light at one point. For this reason, for example, in order to condense light emitted in a divergent state from a point light source that uses light emitted from the tip surface of an optical fiber as a light source, the divergent light beam is collimated to a single point by a rotating parabolic reflecting surface. It is necessary to separately prepare an optical element for converting into a light beam, which is disadvantageous in reducing the size of the optical recording head.
  • the spheroidal reflecting surface described in Patent Document 2 uses, for example, one of the two focal points as a first focal point, condenses divergent light from a point light source disposed at the first focal point, and the other. It is possible to form a light spot at the position of the second focal point. If the shape of the spheroid, the light source, and their arrangement are in an ideal state, a light spot having no aberration is formed. However, the spheroidal reflection surface is highly sensitive to the occurrence of aberrations that cause deterioration of light collection performance with respect to the placement error with the light source, so that the aberration generated in the light spot formed at the position of the second focal point is practical. It is not easy to arrange the light source at the first focal point so as to be within the level.
  • the present invention has been made in view of the above-described problems, and the object of the present invention is to make it possible to easily perform good light collection with little decrease in light collection performance due to an arrangement error with respect to the light source.
  • a compact optical element and an optical recording head including the optical element are provided.
  • the shape of the reflective surface is expressed by the following formula: an optical element.
  • Z ⁇ A m, n ⁇ X m ⁇ Y n
  • the coordinate system of X, Y, Z indicating the following positions is a right-handed system
  • Z Distance from the surface perpendicular to the normal direction at the origin at the origin, which is the position where the principal ray incident on the reflection surface and the reflection surface intersect
  • Y along with the Z axis
  • X Position on the axis perpendicular to the Z axis and Y axis, and passing through the origin
  • ⁇ m sum
  • a m, n for n (m and n are each an integer of 0 or more): m-th order of X and n-th order as
  • the reflection surface is a boundary surface between the optical element and the outside of the optical element, and is a surface on which light passing through the inside of the optical element is reflected.
  • the optical path from the light source to the condensing point is all outside the optical element, 2.
  • an optical recording head that records information by irradiating the information recording medium with light from a light source
  • the optical element according to any one of 1 to 6,
  • the light source A waveguide that guides light from the light source to be coupled to the information recording medium, and a slider that moves relative to the information recording medium
  • the optical recording head wherein the optical element is disposed on the slider so as to couple light from the light source to the waveguide.
  • an optical element that is small in size, has little deterioration in light collection performance due to an arrangement error with respect to a light source, and can easily perform good light collection, and an optical recording head including the optical element. Can be provided.
  • FIG. 1 is a diagram showing a schematic configuration of an optical recording apparatus equipped with an optically assisted magnetic recording head in an embodiment of the present invention. It is sectional drawing which shows the structure of an optical recording head. It is sectional drawing which shows the structure of the optical recording head provided with the optical element which has a reflective surface of another example.
  • A It is an optical path diagram in case a reflective surface comprises a reduction optical system.
  • B It is an optical path diagram in case a reflective surface comprises an equal magnification optical system.
  • C It is an optical path diagram in case a reflective surface comprises an expansion optical system.
  • FIG. 4 is a spherical aberration diagram of Numerical Example 1, wherein (a) shows a design value, (b) shows a case where a positive Y direction eccentricity is generated, and (c) shows a negative direction Y eccentricity. It is a figure which shows the case where this is produced.
  • FIG. 6 is a spherical aberration diagram of Numerical Example 2, wherein (a) shows a design value, (b) shows a case where a positive Y eccentricity occurs, and (c) shows a negative Y eccentricity. It is a figure which shows the case where this is produced.
  • FIG. 6 is a spherical aberration diagram of Numerical Example 2, wherein (a) shows a design value, (b) shows a case where a positive Y eccentricity occurs, and (c) shows a negative Y eccentricity. It is a figure which shows the case where this is produced.
  • FIG. 6 is a spherical aberration diagram of Numerical Example 3, where (a) shows a design value, (b) shows a case where a positive Y eccentricity occurs, and (c) shows a negative Y eccentricity. It is a figure which shows the case where this is produced.
  • FIG. 11 is a spherical aberration diagram of Numerical Example 4, where (a) is a diagram showing design values, (b) is a diagram showing a case where Y direction eccentricity is generated, and (c) is a Y direction eccentricity in negative direction. It is a figure which shows the case where this is produced.
  • FIG. 11 is a spherical aberration diagram of Numerical Example 4, where (a) is a diagram showing design values, (b) is a diagram showing a case where Y direction eccentricity is generated, and (c) is a Y direction eccentricity in negative direction. It is a figure which shows the case where this is produced.
  • FIG. 11 is a spher
  • FIG. 10 is a spherical aberration diagram of Numerical Example 5, where (a) is a diagram illustrating design values, (b) is a diagram illustrating a case where a positive Y eccentricity is generated, and (c) is a negative Y eccentricity. It is a figure which shows the case where this is produced.
  • FIG. 11 is a spherical aberration diagram of Numerical Example 6, wherein (a) is a diagram showing design values, (b) is a diagram showing a case where Y direction eccentricity is generated, and (c) is a Y direction eccentricity in negative direction. It is a figure which shows the case where this is produced.
  • FIG. 11 is a spherical aberration diagram of Numerical Example 6, wherein (a) is a diagram showing design values, (b) is a diagram showing a case where Y direction eccentricity is generated, and (c) is a Y direction eccentricity in negative direction. It is a figure which shows the case where this is produced.
  • FIG. 11 is a spherical aberration diagram of Numerical Example 7, where (a) is a diagram showing design values, (b) is a diagram showing a case where Y direction eccentricity is generated, and (c) is a Y direction eccentricity in negative direction. It is a figure which shows the case where this is produced.
  • 9A and 9B are spherical aberration diagrams of Numerical Example 8, in which FIG. 9A is a diagram illustrating design values, FIG. 9B is a diagram illustrating a case where a positive Y eccentricity is generated, and FIG. It is a figure which shows the case where this is produced.
  • FIGS. 9A and 9B are spherical aberration diagrams of Numerical Example 9, in which FIG. 9A is a diagram illustrating design values, FIG. 9B is a diagram illustrating a case where Y direction eccentricity is generated, and FIG. It is a figure which shows the case where this is produced.
  • the present invention relates to an optical element that deflects light collected in a divergent state from a point light source and collects the light to form a light spot.
  • the present invention relates to deflecting and collecting light emitted from the end face of an optical fiber. It can be used in an optical recording head that records information on a magneto-optical recording medium or an optical recording medium by light.
  • FIG. 1 shows a schematic configuration of an optical recording apparatus (for example, a hard disk apparatus) equipped with an optically assisted magnetic recording head including an optical element according to an embodiment of the present invention.
  • the optical recording apparatus 100 includes the following (1) to (6) in the housing 1. (1) Recording disk (information recording medium) 2 (2) Suspension 4 supported by an arm 5 provided so as to be rotatable in the direction of arrow A (tracking direction) with a support shaft 6 as a fulcrum.
  • Tracking actuator 7 attached to arm 5 and rotationally driving arm 5 (4) Optically assisted magnetic recording head attached to the tip of the suspension 4 (hereinafter referred to as the optical recording head 3) (5) Motor for rotating the disk 2 in the direction of arrow B (not shown) (6) Control unit 8 for controlling the optical recording head 3 such as generation of light and magnetic field to be irradiated in accordance with write information for recording on the tracking actuator 7, motor and disk 2.
  • the optical recording apparatus 100 is configured such that the optical recording head 3 can move relatively while flying over the disk 2.
  • FIG. 2 shows a cross section of the optical recording head 3 together with the peripheral portion.
  • An optical recording head 3 is fixed to the tip of the suspension 4.
  • the optical recording head 3 mainly includes a slider 32 and a prism 31 which is an optical element according to the present invention.
  • the slider 32 is provided with a waveguide 40, and a magnetic recording portion 42 is provided on the side of the flow of the disk 2 immediately after that (in the direction of the arrow shown in FIG. 2 in FIG. 2).
  • Light 50 emitted from a light source (not shown) such as a semiconductor laser is guided to the prism 31 by using an optical fiber 33 or a polymer waveguide as a linear light guide.
  • the prism 31 includes a V groove 31 b for positioning the optical fiber 33 and a reflecting surface 31 a for deflecting light emitted from the optical fiber 33.
  • the optical fiber 33 is fixed to the V groove 31 b and the prism 31 is fixed to the upper surface of the slider 32.
  • the optical fiber 33 is easily and accurately positioned relative to the reflecting surface 31a of the prism 31 by the V-groove 31b.
  • the optical fiber 33 is emitted from the optical fiber 33 and deflected by the reflecting surface 31a.
  • the emitted light is reliably guided to the incident surface (upper end surface) of the waveguide 40 provided on the slider 32 and collected.
  • the waveguide 40 includes a core part and a clad part having a lower refractive index than the core part.
  • the light spot formed on the upper end surface of the waveguide 40 by the light emitted from the prism 31 is guided by the waveguide 40 and emitted from the optical recording head 3 toward the disk 2.
  • the specific material constituting the waveguide 40 and its refractive index depend on the wavelength of the light source to be used. For example, in the communication wavelength band of wavelengths 1.5 ⁇ m and 1.3 ⁇ m, Si ( Examples of the clad material include SiOx (refractive index: 1.4 to 3.48) and Al 2 O 3 (refractive index: 1.8).
  • the prism 31 includes a recess having a part of the inner wall surface as a reflecting surface 31a, and divergent light emitted into the recess from the tip surface of the optical fiber 33 where the light source is regarded as a point is air in the space formed by the recess. It goes inside and enters the reflecting surface 31a.
  • the optical fiber 33 is mentioned as an example as a point light source, it is not limited to this, You may arrange
  • the semiconductor laser disposed in place of the optical fiber 33 is not limited to the semiconductor laser chip, but may be a semiconductor laser module including a light receiving unit that receives reflected light from a disk for controlling tracking of the optical recording head, for example. .
  • the reflection surface 31a has a function of deflecting incident light emitted from a light source and a function of condensing the deflected light at one point, and has a shape represented by the following equation (1).
  • the light incident on the reflecting surface 31 a is deflected, and is collected and coupled to the incident surface (upper end surface) of the waveguide 40 provided on the slider 32.
  • the reflecting surface 31a represented by the formula (1) is not simply a spheroid replaced with an XY polynomial, divergent light from a single point, which is light from the light source, is incident, similar to the spheroid.
  • the light beam can be deflected and collected at one point.
  • FIG. 2 shows a state in which the chief ray incident on the reflecting surface 31a is deflected by approximately 90 °.
  • the deflection angle ⁇ representing the angle at which the principal ray is deflected is an angle formed in a plane formed by the principal ray incident on the reflecting surface 31a and the reflected principal ray.
  • Setting the deflection angle ⁇ to approximately 90 ° (about 90 ° ⁇ 5 °) means that the optical fiber 33 is disposed on the prism 31, the reflective surface 31 a is disposed, the shape of the slider 32 on which the prism 31 is mounted, and the slider 32. This is preferable because the waveguide 40 is easily arranged, the parts related to the arrangement are easily processed, and the optical recording head mainly composed of the prism 31 and the slider 32 can be downsized.
  • the reflecting surface 31a has a shape in which the performance degradation due to the relative positional deviation with respect to the light source is smaller than the performance degradation due to the relative positional deviation between the light source and the spheroid. For this reason, the tolerance
  • the non-zero aspherical coefficient A0,3 is used so that necessary performance is ensured and performance degradation due to misalignment is suppressed. Note that the fact that the aspheric coefficient A 0,3 is not zero indicates that the reflecting surface 31a has a shape different from the spheroid.
  • the optical recording head 3 that can efficiently use light can be easily assembled.
  • the Z position shown in the expression (1) representing the reflecting surface 31a is directly expressed by X and Y, a processing error due to approximation such as interpolation at the time of processing the reflecting surface 31a hardly occurs. Although it depends on the apparatus, it is easy to create processing data, and the processing of the reflecting surface 31a can be easily performed with high accuracy for the design.
  • the prism 31 has a structure that passes all the way from the tip surface of the optical fiber 33 to the condensing point in the air, and can easily process the reflecting surface 31a to be a mirror surface that reflects light well. It can produce with materials, such as.
  • the prism 31 made of such a material can be used as it is after the material has been processed without the need to apply a special surface treatment or an increased reflection film to the reflecting surface 31a. Can be done automatically.
  • the prism 31 is not limited to a material that can reflect light, such as the metal described above, and may be a material such as resin or glass that transmits light. In this case, the metal that reflects light to the reflective surface 31a.
  • a film or the like is provided (for example, gold, silver, aluminum, or the like).
  • the material of the prism 31 is a resin
  • it can be formed by, for example, an injection molding method or a press molding method using a thermoplastic resin as a material.
  • thermoplastic resin include ZEONEX (registered trademark) 480R (Nippon Zeon Co., Ltd.), PMMA (polymethyl methacrylate: for example, Sumipex (registered trademark) MGSS, Sumitomo Chemical Co., Ltd.), PC (polycarbonate: for example, Panlite (registered trademark) AD5503, Teijin Chemicals Ltd.) and the like.
  • the reflecting function of the reflecting surface 31a is not limited to the above-described mirror-finished metal or the like, and a material forming the prism 31A, air, and the like, like a prism 31A shown as another optical element in FIG. You may utilize the reflection effect by the difference in refractive index.
  • the light emitted from the optical fiber 33 enters the prism 31A made of a material (glass, the above-described resin, etc.) having a refractive index larger than that of air, and the deflecting unit deflects the optical path on the optical path of the incident light.
  • the boundary surface with air becomes the reflecting surface 31a and is deflected.
  • the prism 31A can be easily manufactured using a mold made of resin or glass having a refractive index larger than that of air, and can be light and low in cost.
  • the entire optical path from the position where light is emitted from the optical fiber 33 to the light is made of a material having a refractive index larger than that of air. It is not necessary to have the whole on the road, and it is sufficient if there is a portion made of the material in a portion where light passing through the prism 31A is deflected.
  • the prism 31A is made of a material having a refractive index with respect to the used wavelength of 1.41 or more, the reflection at the reflecting surface 31a can be made total reflection.
  • total reflection for the reflecting surface 31a, there is no need to perform additional processing such as a reflection-increasing film on the reflecting surface 31a, and a high reflectance can be secured. Can be used with high efficiency.
  • the refractive index of the material of the prism 31A in the reduction optical system (see FIG. 4A), the smaller the magnification (the absolute value of the magnification shown in the numerical examples in the examples described later) is.
  • a material having a high refractive index is required.
  • the magnification is 0.5
  • a material having a refractive index of about 1.5 is required.
  • the reflection surface 31a can be totally reflected even with a material having a lower refractive index by making the deflection angle ⁇ an obtuse angle larger than 90 °.
  • the reflection surface 31a can be made total reflection by making the deflection angle ⁇ an obtuse angle of about 95 °. it can.
  • the exit end face of the optical fiber 33 and the incident face of the prism 31A are joined with an adhesive having a refractive index close to the respective refractive index without any gap, and similarly, light from the prism 31A is transmitted.
  • an adhesive having a refractive index close to the respective refractive index without any gap
  • the light guided to the optical fiber 33 is suppressed to a loss and efficiently guided to the waveguide 40. be able to.
  • the prisms 31 and 31A that have been described so far and can be easily processed have a small volume and have a deflection function and a light condensing function, they are very effective in configuring a small optical recording head. .
  • it is optimal as an optical element for coupling light guided from the optical fiber 33 or the semiconductor laser to the slider 32 provided with the waveguide 40.
  • the NA on the light source side of the reflecting surface 31a is made large enough to correspond to the NA on the emission side of the optical fiber 33, and the NA on the light condensing side does not need to be extremely large, and the waveguide 40 provided in the slider 32 is efficient. It is only necessary to form a light spot diameter that can be well coupled. With such a reflection surface 31a, light for sufficiently irradiating the information recording medium can be guided from the optical fiber 33 by being deflected and condensed.
  • the light coupled to the waveguide 40 propagates in the waveguide 40 in the direction of the disk 2, reaches the emission surface (lower end surface) of the waveguide 40, and is emitted toward the disk 2.
  • the magnetic recording unit 42 applies a magnetic field to perform optically assisted magnetic recording.
  • a plasmon probe (not shown) that is a minute metal structure that generates near-field light by light propagating through the waveguide 40 may be provided in the vicinity of the exit surface of the waveguide 40.
  • the light coupled to the plasmon probe generates near-field light at the tip of the plasmon probe exposed at the exit surface of the waveguide 40.
  • the generated minute spot of the near-field light performs a higher-density optically assisted magnetic recording by heating a smaller area of the disk 2 to reduce the holding force and then applying a magnetic field by the magnetic recording unit 42. .
  • the waveguide 40 and the magnetic recording unit 42 are arranged in this order from the entry side to the exit side (in the direction of the arrow 2a in the figure) of the recording area of the disk 2.
  • the magnetic recording unit 42 is located immediately after the exit side of the waveguide 40 because the magnetic recording can be performed before the heated recording area is cooled too much.
  • a magnetic reproducing unit (not shown) for reading magnetic recording information written on the disk 2 may be provided on the exit side of the magnetic recording unit 42 or the inflow side of the waveguide 40.
  • the thickness of the prism 31 mounted on the upper portion of the slider 32 is desirably 200 ⁇ m or less, and a small optical recording head 3 can be obtained by combining the slider 32 and the prism 31.
  • the embodiment described above relates to an optically assisted magnetic recording head and an optically assisted magnetic recording apparatus.
  • the main configuration of the embodiment is an optical recording head having an information recording medium as an optical recording disk, It can also be used for an optical recording apparatus.
  • the slider does not require a magnetic recording unit and a magnetic reproducing unit.
  • FIG. 4 shows an optical path diagram from the light source to the condensing point in Numerical Examples 1 to 9.
  • 4A shows the optical path of the reduction system (numerical examples 3, 4, 7 to 9)
  • FIG. 4B shows the same-magnification system (numeric examples 2 and 6)
  • FIG. 4C shows the optical path of the enlargement system (numeric examples 1 and 5).
  • the figure shows a light source position as a surface S1, a reflection surface as a surface S3, and a condensing point as an image surface as a surface S5.
  • dummy surfaces S2 and S4 are provided for convenience of calculation.
  • the optical path from the surface S1 to the surface S5 is in the air (the refractive index column of each numerical example is blank), and the numerical examples 4 to 9 are Like the prism 31A shown in FIG. 3, the optical path from the surface S1 to the surface S5 is in a material having a refractive index higher than that of air.
  • the material whose refractive index is larger than air is assumed to be PC (polycarbonate), and in the numerical examples 5, 6, and 8, the refractive index of the prism 31A is larger than air, the material being PMMA (polymethyl methacrylate). ) Is assumed.
  • FIG. 4A shows the deflection angle ⁇ .
  • a deflection angle is defined as an angle formed by an incident principal ray and an emitted principal ray within a deflection plane formed by a principal ray incident on the surface S3 and a ray (principal ray) that is deflected and emitted from the surface S3.
  • ⁇ The deflection angle ⁇ in FIGS. 4B and 4C is the same as that in FIG.
  • the deflection angle ⁇ is 90 ° in numerical examples 1 to 7, and is an obtuse angle exceeding 90 ° in numerical examples 8 and 9.
  • FIG. 4 (a) shows the coordinate system for each of the surface S1, surface S3, and surface S5 in all numerical examples
  • FIGS. 4 (b) and 4 (c) are the same as FIG. 4 (a). Omitted.
  • the performance is remarkably lowered even if the relative positional deviation from the light source of the conventional spheroid is about 0.1 ⁇ m.
  • the surface position tolerance described in each numerical example is such that a wavefront aberration equivalent to that generated when the relative position between the spheroidal reflection surface and the light source is shifted by 0.1 ⁇ m from the design position is generated. Shows the amount of displacement by shifting the relative position between the surface S3 and the light source.
  • the direction of shifting the relative position is the Y-axis direction for both the spheroid and the surface S3. This is because the shape in the Y-axis direction is not symmetrical from the design position in both the spheroidal surface and the surface S3, and therefore, the positional deviation in the Y-axis direction is degraded in performance compared to the X-axis and Z-axis directions. This is because it is a more generated direction.
  • FIGS. 5 to 13 The spherical aberrations obtained from the calculation results in Numerical Examples 1 to 9 are shown in FIGS. 5 to 13, respectively.
  • the vertical axis H is normalized by assuming that the maximum axial light beam diameter is 1 on the surface S2.
  • (A) in each of FIGS. 5 to 13 shows a design value
  • (b) shows a case where the surface S3 is shifted in the plus Y direction by the surface position allowable error amount
  • (c) shows the surface in the minus Y direction. The case where the surface S3 is shifted by the position allowable error amount is shown.
  • aspherical coefficients A m, n are, for convenience of description, the following Am, n: represented as (Example A0,1, etc.).
  • the unit of parallel eccentricity is mm, and the unit of rotation is ° (degrees).
  • the surface position tolerance value is significantly larger than that of the spheroid surface, and it is possible to collect light better than the spherical aberration diagram. Has been. For this reason, it has been confirmed that the prisms 31 and 31A including the reflecting surface 31a having the shape of the surface S3 have a large arrangement tolerance with the light source and can perform good light collection.

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  • Physics & Mathematics (AREA)
  • Optics & Photonics (AREA)
  • Electromagnetism (AREA)
  • Engineering & Computer Science (AREA)
  • Manufacturing & Machinery (AREA)
  • Magnetic Heads (AREA)
  • Adjustment Of The Magnetic Head Position Track Following On Tapes (AREA)
  • Optical Head (AREA)
  • Lenses (AREA)

Abstract

L'invention porte sur un élément optique de petite dimension, qui présente une faible chute de réduction d'efficacité de concentration de lumière provoquée par une erreur de placement par rapport à la source de lumière, et qui concentre facilement correctement la lumière. L'élément optique comporte une surface réfléchissante qui dévie une lumière divergente émise à partir de la source de lumière et concentre la lumière au niveau d'un point focal, la forme de la surface réfléchissante étant décrite dans la formule (1).
PCT/JP2010/051602 2009-03-02 2010-02-04 Élément optique et tête d'enregistrement optique WO2010100994A1 (fr)

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Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012042767A1 (fr) * 2010-09-27 2012-04-05 コニカミノルタオプト株式会社 Procédé de fabrication d'un élément optique, tête optique et dispositif d'enregistrement d'informations

Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03102655A (ja) * 1989-09-14 1991-04-30 Sony Corp 光学ピックアップ装置
JP2003045004A (ja) * 2001-07-27 2003-02-14 Fuji Xerox Co Ltd 光アシスト磁気ヘッド及び光アシスト磁気ディスク装置

Patent Citations (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH03102655A (ja) * 1989-09-14 1991-04-30 Sony Corp 光学ピックアップ装置
JP2003045004A (ja) * 2001-07-27 2003-02-14 Fuji Xerox Co Ltd 光アシスト磁気ヘッド及び光アシスト磁気ディスク装置

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO2012042767A1 (fr) * 2010-09-27 2012-04-05 コニカミノルタオプト株式会社 Procédé de fabrication d'un élément optique, tête optique et dispositif d'enregistrement d'informations

Also Published As

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