WO1993016469A1 - Phase varying device, and optical pickup apparatus using the same for magneto-optical storage - Google Patents
Phase varying device, and optical pickup apparatus using the same for magneto-optical storage Download PDFInfo
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- WO1993016469A1 WO1993016469A1 PCT/JP1993/000158 JP9300158W WO9316469A1 WO 1993016469 A1 WO1993016469 A1 WO 1993016469A1 JP 9300158 W JP9300158 W JP 9300158W WO 9316469 A1 WO9316469 A1 WO 9316469A1
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Classifications
-
- 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
- G11B7/13—Optical detectors therefor
- G11B7/131—Arrangement of detectors in a multiple array
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/04—Prisms
-
- G—PHYSICS
- G02—OPTICS
- G02B—OPTICAL ELEMENTS, SYSTEMS OR APPARATUS
- G02B5/00—Optical elements other than lenses
- G02B5/30—Polarising elements
- G02B5/3083—Birefringent or phase retarding elements
-
- G—PHYSICS
- G11—INFORMATION STORAGE
- G11B—INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER
- G11B11/00—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor
- G11B11/10—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field
- G11B11/105—Recording on or reproducing from the same record carrier wherein for these two operations the methods are covered by different main groups of groups G11B3/00 - G11B7/00 or by different subgroups of group G11B9/00; Record carriers therefor using recording by magnetic means or other means for magnetisation or demagnetisation of a record carrier, e.g. light induced spin magnetisation; Demagnetisation by thermal or stress means in the presence or not of an orienting magnetic field using a beam of light or a magnetic field for recording by change of magnetisation and a beam of light for reproducing, i.e. magneto-optical, e.g. light-induced thermomagnetic recording, spin magnetisation recording, Kerr or Faraday effect reproducing
- G11B11/10532—Heads
- G11B11/10541—Heads for reproducing
- G11B11/10543—Heads for reproducing using optical beam of radiation
-
- 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
- G11B7/123—Integrated head arrangements, e.g. with source and detectors mounted on the same substrate
-
- 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
- G11B7/1356—Double or multiple prisms, i.e. having two or more prisms in cooperation
-
- 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
- G11B7/1359—Single prisms
-
- 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
- G11B7/1365—Separate or integrated refractive elements, e.g. wave plates
- G11B7/1367—Stepped phase plates
Definitions
- the present invention relates to a phase change device such as a phase delay type prism and a compound optical rotation plate, and an optical pickup device used for an optical disk device using the same, and more particularly to reproducing information recorded on a magneto-optical recording medium ( ⁇ ⁇ ).
- the present invention relates to an optical pickup device suitable for a magneto-optical storage device and a phase difference generating device used for the optical pickup device.
- An optical pickup device for a magneto-optical storage device for reproducing information recorded on a magneto-optical recording medium, for example, a magneto-optical disk irradiates a linearly polarized laser beam onto a recording surface of the magneto-optical disk to record data.
- the information recorded as the magnetization direction on the surface is detected by changing the polarization plane rotation by the electro-optic Kerr effect or Faraday effect, which is the interaction between light and magnetization.
- Such an optical pickup device for a magneto-optical storage device is an optical pickup device that reproduces information from a compact disk (CD), such as a read-only optical disk, a write-once optical disk, and a phase-change optical disk. Based on This is different from the optical pickup device for optical recording / reproducing devices that detects the change in reflected light amount.
- the optical pickup device refers to an optical pickup device for a magneto-optical storage device.
- a polarizing beam splitter is known as an optical element that can provide desired characteristics even when it is put in convergent light.However, it is difficult to separate MO signals using a polarizing beam splitter.
- several methods are known as follows.
- Conventional optical pickup devices for magneto-optical storage devices include, for example, a semiconductor laser, a collimating lens that collimates light emitted from the semiconductor laser, and a collimating lens that collimates light.
- An objective lens that condenses the emitted light and irradiates the recording surface of the magneto-optical disk, and a part of the reflected light that is disposed between the semiconductor laser and the objective lens and that is reflected by the recording surface of the magneto-optical disk.
- a polarization beam splitter (hereinafter, referred to as a first polarization beam splitter) to be separated, and an analyzer that detects a part of the reflected light separated by the first polarization beam splitter,
- a photoelectric conversion element that detects the level of light transmitted through this analyzer (Hereinafter referred to as a detector), collects the light emitted from the semiconductor laser and irradiates the light onto the recording surface of the magneto-optical disk, and separates a part of the reflected light reflected by this recording surface.
- the level of a component having a predetermined polarization plane, that is, a predetermined light vibration plane, of a part of the separated reflected light is detected, and information recorded on the magneto-optical disk is detected from the component.
- a predetermined polarization plane that is, a predetermined light vibration plane
- information recorded on the magneto-optical disk is detected from the component.
- each component of the reflected light separated by the first polarization beam splitter that is, a component having the same vibration surface as the emitted light from the laser, is a so-called component.
- the P-wave component and the S-wave component having a vibration direction orthogonal to the P-wave component are separated by a half-wave plate and a second polarizing beam splitter instead of the analyzer, and the separated quadrature is separated.
- the level of each of the S-wave component and the P-wave component is detected by two detectors, the level difference between them is detected by a differential amplifier, and the information recorded by the differential method is detected.
- An optical pick-up device for a magneto-optical storage device using a 1Z2 wavelength plate and a second polarizing beam splitter instead of this analyzer is a laser beam splitting from reflected light by a first polarizing beam splitter. Since the S wave component of the beam is a magneto-optical signal (hereinafter referred to as MO signal), it is desirable to set the reflectance of the first polarized beam splitter to the S wave to 100%.
- MO signal magneto-optical signal
- the reflectivity for the wave component is set so that the amount of light incident on the detector and the noise due to the detector shot noise and the birefringence of the disk substrate are balanced. There is a problem that the power ringing efficiency is low. Further, in order to separate the laser beam separated by the first polarization beam splitter into two components by the second polarization beam splitter, it is necessary to establish an optical path thereof. The dimensions are large and it is difficult to reduce the size of the optical pickup device. Further, it is difficult to perform a coating for polarization separation of the polarization beam splitter. For example, a coating technique for reducing the phase difference between the P wave and the S wave is very difficult. The polarizing beam splitter must be placed in parallel light, and a collimating lens is required.
- an optical pickup device for a magneto-optical storage device that uses a peristron prism instead of the above-described analyzer instead of the half-wave plate and the second polarization beam splitter is also known.
- the optical pick for this magneto-optical storage device The up device has also encountered the same problem as the optical pickup device for the magneto-optical storage device using the one-two wavelength plate and the second polarizing beam splitter. Disclosure of the invention
- the optical pickup device for a magneto-optical storage device of the present invention uses a phase changing means such as a half-wave plate, a phase difference generating prism, and a complex optical rotation plate.
- a laser light source a polarizing beam splitter, an objective lens, and a photodetector arranged along the optical axis.
- the emitted light is emitted as convergent light onto the recording surface of the magneto-optical recording medium, and a predetermined polarization component of the reflected light from the recording surface of the magneto-optical recording medium is separated by the polarization beam splitter to produce the light.
- an optical pick-up device that takes out light with a detection element
- phase change means is provided,
- an optical pickup device for a magneto-optical storage device characterized in that the light changed by the phase changing means is detected through the polarization beam splitter and the photodetector.
- the phase changing means includes a vibration surface having a predetermined angle with respect to the optical axis on a plane orthogonal to the optical axis, divided into at least two portions with the optical axis as a boundary. , C t axis C axis relative to those of the optical axis, it has two divided regions to C 2 axis, Shako out from the laser light source passes through one division region, serial of the magneto-optical recording medium It is possible to use a half-wave plate arranged so that the light reflected by the recording surface passes through the other divided area.
- the light detection element is divided into four parts around the optical axis corresponding to the division of the half-wave plate, and preferably, a part corresponding to the optical axis does not have a detection part. It is divided into four and recorded on the magneto-optical recording medium from the detection signal of the four divided areas. Detects the recorded magneto-optical (MO) recording signal.
- MO magneto-optical
- the one- and two-wavelength plates are mounted on a surface of the polarizing beam splitter on the objective lens side.
- a light detection element having a large light receiving area is provided on a surface of the polarization beam splitter orthogonal to a surface provided with the 12-wavelength plate.
- a hologram laser unit with a focus error detection function is used as the laser light source.
- the polarization beam splitter it is preferable to use a polarization beam splitter in which the phase difference between the polarization P-wave component and the polarization S-wave component is almost 0 °.
- the angle of the vibrating surface in the two divided regions of the 12 wavelength plate is made different, and a light detecting element such as an avalanche photodiode (APD) having a non-divided light receiving surface is used as the light detecting element.
- a light detecting element such as an avalanche photodiode (APD) having a non-divided light receiving surface is used as the light detecting element.
- APD avalanche photodiode
- the optical pickup device for a magneto-optical storage device has a surface having a predetermined inclination angle, a first parallel surface for reflecting light incident from the surface at a first position, and a first parallel surface at the first position.
- a micro-prism configured to reflect light at a front of said first parallel plane;
- a photodetector provided in correspondence with the first position and the second position, each having a central portion and three divided regions divided into three on both sides thereof;
- Using a laser coupler integrally formed on the same semiconductor substrate with a laser light source provided to face the inclined surface the laser light source incident on the inclined surface of the micro prism is reflected on the side where the light from the laser light source is reflected.
- a first mirror provided, and a second mirror which faces the reflection surface of the first mirror and receives reflected light from the first mirror and emits the light in a direction orthogonal to the first mirror.
- the C axis for those optical axes is C! Axis and C 2 axes, the light emitted from the second mirror passes through one of the divided areas, and the reflected light reflected by the recording surface of the magneto-optical recording medium It is preferable to provide a 1Z2 wavelength plate disposed so as to pass through the other divided region.
- the optical pickup device for a magneto-optical storage device includes two differential amplifiers for detecting a differential signal from each of the three divided areas of the two photodetectors, and further differentially outputs signals output from these differential amplifiers. And a third differential amplifier for amplifying.
- the laser light source includes a plurality of divided regions that are divided into at least two on a plane that is orthogonal to each other and have predetermined phase difference characteristics, and light emitted from the laser light source passes through one of the divided regions, It is possible to use a phase difference generating device having a phase difference generating film arranged so that the light reflected by the recording surface of the recording medium passes through the other divided area.
- the thickness of the phase difference generating film is adjusted to change the phase difference.
- the phase changing means has at least two divided areas on a plane orthogonal to the optical axis, and emits light from the laser light source to one area by right-rotating the light by a predetermined angle. Alternatively, it is disposed so that the reflected light reflected by the recording surface of the magneto-optical recording medium is passed through the other area by a predetermined angle in a direction opposite to the above-described rotation. Can be used.
- the optical rotation angle of the composite optical rotation plate is defined by the material and thickness of the composite optical rotation plate.
- the composite optical rotation plate is divided by a line parallel to the pit formation direction of the recording surface of the magneto-optical disk.
- the phase change characteristic is adjusted by setting the optical rotation angles of the divided left optical rotation plate and the right optical rotation plate to predetermined values, or (2) the recording surface of the magneto-optical disk.
- the phase change characteristic is adjusted by using a split composite optical rotation plate divided by a line orthogonal to the direction in which the light is formed, and setting the optical rotation angles of the divided left optical rotation plate and the right optical rotation plate to predetermined values.
- the optical rotation angle of the composite optical rotation plate is set to about 10 ° or more, and to 22.5 ° in the latter stage.
- the 45-degree prism and the 45-degree prism are divided into at least two on a plane that is attached to the reflection surface of the 45-degree prism and that is orthogonal to the optical axis and has predetermined phase difference characteristics with each other.
- a phase difference generating device having a plurality of divided regions and causing a predetermined phase difference between light incident on one divided region and light emitted from the other region is proposed.
- At least two divided regions on a plane orthogonal to the optical axis there is provided at least two divided regions on a plane orthogonal to the optical axis, and the light incident on one of the regions is rotated right or left by a predetermined angle.
- a composite optical rotation plate is provided, which is formed so that light incident on the other region is rotated by a predetermined angle in a direction opposite to the above-mentioned optical rotation and is rotated therethrough.
- the angle of rotation of the optical rotation plate is defined by the material and thickness of the composite optical rotation plate.
- FIG. 1 is a plan view of an optical pickup device as a first embodiment of an optical pickup device for a magneto-optical storage device according to the present invention.
- FIG. 2 shows C in two regions constituting a half-wave plate constituting the optical pickup device of the first embodiment of the present invention.
- FIG. 3 is a diagram showing a first form of a laser beam vector for describing the operation principle of the optical pickup device according to the first embodiment of the present invention.
- FIG. 4 is a diagram illustrating a second form of a laser beam vector for explaining the operation principle of the optical pickup device according to the first embodiment of the present invention.
- FIG. 5 is a diagram showing a third mode of a laser beam vector for explaining the operation principle of the optical pickup device according to the first embodiment of the present invention.
- FIG. 6 is a diagram schematically showing a light receiving region of a detector constituting the optical pickup device according to the first embodiment of the present invention.
- FIG. 7 shows an optical pickup device according to a first embodiment of the present invention.
- FIG. 4 is another configuration diagram of a polarizing beam splitter, a 12-wavelength plate, and a detector.
- FIG. 8 shows a planar configuration of an optical pickup device as a first modification of the first embodiment of the present invention, using the polarization beam splitter, the half-wave plate and the detector shown in FIG. FIG.
- FIG. 9 is a laser beam vector for explaining the relationship between the C 1 axis and the C 2 axis in two regions constituting the half-wave plate constituting the optical pickup device according to the first embodiment of the present invention.
- FIG. 10 is another configuration diagram of the half-wave plate constituting the optical pickup device of the first embodiment of the present invention.
- FIG. 11 is a plan view of an optical pickup device using the 1Z2 wavelength plate shown in FIG. 10 as a second modification of the first embodiment of the present invention.
- FIG. 12 is a plan view of an optical pickup device as a modification of the optical pickup device shown in FIG.
- FIG. 13 is a side view of an optical pickup device as a third modification of the optical pickup device according to the first embodiment of the present invention.
- FIG. 14 is a configuration diagram of a laser power bubbler included in the optical pickup device shown in FIG.
- FIG. 15 shows the laser power puller shown in Fig. 13.
- FIG. 4 is a diagram schematically showing a light receiving region in a detection zone.
- FIG. 16 is a plan view of an optical pickup device as a fourth modification of the optical pickup device according to the first embodiment of the present invention.
- FIG. 17 is a plan view of an optical pickup device as a second embodiment of the optical pickup device for a magneto-optical storage device of the present invention.
- FIGS. 18a to 18c are configuration diagrams of the combined phase delay prism (CPR) shown in FIG.
- FIG. 19 is a diagram illustrating the path of light passing through the combined phase delay prism (CPR) shown in FIG. 17 and its characteristics.
- CPR phase delay prism
- FIGS. 20a to 20d are diagrams showing the characteristics of the light shown in FIG.
- FIG. 21 is a partial configuration diagram of a second embodiment of the second embodiment of the optical pickup device for a magneto-optical storage device according to the present invention.
- FIG. 22 is a plan view of an optical pickup device as a third embodiment of the optical pickup device for a magneto-optical storage device of the present invention.
- FIGS. 23A and 23B are diagrams illustrating a method of manufacturing the optical rotation member shown in FIG.
- FIGS. 24a and 24b are diagrams illustrating specific optical rotation members.
- FIGS. 25 and 26 show the magneto-optical storage device of the present invention.
- FIG. 11 is a diagram illustrating a ray trajectory in a third embodiment of the optical pickup device.
- FIG. 27 is a diagram showing signal processing in the optical pickup device shown in FIG. 25 and FIG.
- FIG. 28 is a sectional view showing the configuration of an optical pickup device according to a third embodiment of the optical pickup device for a magneto-optical storage device of the present invention.
- FIG. 29 is a partially enlarged configuration diagram of the optical pickup device shown in FIG.
- FIGS. 30 and 31 are a schematic configuration perspective view and a ray trajectory of an optical pickup device according to a fourth embodiment of the optical pickup device for a magneto-optical storage device of the present invention.
- FIGS. 32a to 32e are characteristic diagrams of the composite optical rotation plate shown in FIGS. 30 and 31.
- FIG. 32a to 32e are characteristic diagrams of the composite optical rotation plate shown in FIGS. 30 and 31.
- FIG. 33 is a diagram illustrating the signal components of the composite optical rotation plate shown in FIGS. 32A to 32E.
- FIGS. 34a and 34b are diagrams illustrating the signal components in the X and y directions of the composite optical rotation plate shown in FIGS. 32a to 32e.
- FIG. 35 is a diagram illustrating division of the composite optical rotation plate according to the first embodiment of the fourth embodiment of the present invention.
- FIGS. 36a to 36m are diagrams illustrating the ray trajectory in FIG. 35.
- FIG. 37 shows a composite of the second embodiment of the fourth embodiment of the present invention. It is a figure which illustrates division
- FIG. 38 a to FIG. 38 i are diagrams illustrating the ray trajectory in FIG. 37.
- FIGS. 39a and 39b are graphs showing simulation results of the MO signal and the sum signal of the composite optical rotation plate of the fourth embodiment of the present invention.
- FIG. 40 is a standardized version of the graph illustrated in FIG. 39b.
- FIG. 41 a and FIG. 41 b are graphs showing theoretical values and measured values of the composite optical rotation plate according to the fourth embodiment of the present invention.
- FIG. 42 is a graph showing the MTF of the composite optical rotation plate of the related art and the fourth example of the present invention.
- An optical pickup device for a magneto-optical storage device according to the present invention
- FIG. 1 is a plan view of an optical pickup device as a first embodiment of an optical pickup device for a magneto-optical storage device of the present invention used when reproducing information recorded on a magneto-optical recording medium, for example, a magneto-optical disk.
- FIG. 3 is a diagram illustrating a configuration.
- This optical pickup device collects a laser light source 11, a collimating lens 12 for collimating the light emitted from the laser light source 11, and a collimating lens 12 for collimating the lens 12.
- the objective lens 13 irradiates the recording surface 1 a of the magneto-optical disk 1 with light, and is disposed between the laser light source 11 and the objective lens 13, and the recording surface 1 a of the magneto-optical disk 1 is provided.
- a polarizing beam splitter (PBS) 14 that separates a predetermined polarization component of the reflected light reflected by the optical disc 1 and a polarizing beam splitter 14 that is disposed between the polarizing beam splitter 14 and the magneto-optical disc 1 and has an optical axis 0 - 0, each of the C-axis in the two divided respective areas 1 5 a, 1 5 b at least on the flat surface to the left and right (or top and bottom) perpendicular to, that is, the d-axis and C 2 axis
- the 12-wavelength plate 15 set at different angles and the specified beam splitter 14
- a photoelectric conversion element (hereinafter referred to as a detector) 16 as a light detection element for detecting the level of a light component, and a polarization beam splitter 14 and a detector 16 are disposed between the polarization detector and the polarization detector. : ⁇
- the laser light source 11 is composed of, for example, a semiconductor laser.
- the collimating lens 12 converts the light emitted from the laser light source 11 into parallel light and enters the polarized beam splitter 14
- the laser light source 11 Outputs a P wave whose polarization plane (oscillation direction) is parallel to the P axis, for example.
- the reflectance of the polarized beam splitter 14 is 0% for the P wave and 100% for the S wave.
- the transmittance of the polarization beam splitter 14 is 100% for the P wave and 0% for the S wave. Therefore, the polarization beam splitter 14 transmits 100% of the outgoing light, which is a P-wave from the laser light source 11, and the P-wave transmitted through the polarization beam splitter 14 becomes a 1Z2 wave plate 15 Is incident on.
- Wave plate 15 is a plane perpendicular (orthogonal) to the optical axis. At least on the plane 2 divided regions 1 5 a, has a 1 5 b, C axis in each region, that is, a d-axis and C 2 axis and the different angles.
- the 12-wavelength plate 15 has a boundary between the two divided regions 15a and 15b on a plane orthogonal to the optical axis 0—0 ′.
- -Through 0 ' parallel to the S-axis, and the C-axis, which is the fast axis of the 1-dual-wavelength plate 15, is at 45 degrees to the P-axis in the first divided region 15a.
- a first axis having an angle hereinafter, this axis is referred to as d axis
- d axis a second axis having an angle of 12.5 degrees with respect to the P axis in the second divided region 15b. have) that C 2 axis of this shaft.
- the light component passing through the first divided area 1 5 a of the P-wave from a polarizing one Musupuri Tsu evening 1 4 (hereinafter, referred to as a laser beam I t) is, for example,
- a component (hereinafter, referred to as a laser beam I 2 ) of the P wave from the polarization beam splitter 14 that passes through the second divided region 15 b is, as shown in FIG. of the the child passes through the divided region 1 5 b,
- Le vibration surface the vibration direction is converted so as to be line-symmetrical with the C 2 axis has an angle one 4 5 degrees relative to axis P - Zabimu I 2 1
- the beam After being converted into an S-wave laser beam I and a laser beam I 21 having a vibration direction of 144 degrees with respect to the P-axis, respectively, the beam is converged by the objective lens 13 and is magneto-optical Irradiates the recording surface 1a of the disc 1.
- Storage surface 1 a of the magneto-optical disc 1 stores are magnetized in a predetermined orientation based on the information, the laser beam I n, I 2 1 to be reflected on the recording surface 1 a of the magneto-optical disk 1 Therefore, the direction of oscillation is rotated by 10 degrees as shown in FIGS. 3 and 4 due to the interaction between light and magnetization, for example, the “electro-optical force-effect”, and the laser beam I n, with vibration surface for one 21 it is converted into a laser beam I 12, I 22, which is one of 0 degrees, respectively, their optical paths and the forward and backward paths are reversed in the optical axis 0 0, the bordering.
- laser Zabimu I 12 is a reflected light of the laser beam I u is through the right on the paper with respect to the optical axis 0 0 'in FIG. 1, a reflected light of the laser beam I 2 i
- Laser beam I 22 passes through the left side on the paper relative to the optical axis 0 0 '.
- the laser beams I 12 and I 22 reflected by the storage surface 1 a of the magneto-optical disk 1 are collimated by the objective lens 13, and then enter the 1 Z2 wavelength plate 15 again.
- These laser beams I 1S and I 23 are incident on the polarization beam splitter 14 .
- the polarization beam splitter 14 has a reflectance of 0% and 100% for the P wave and the S wave, respectively. Ichimu I 1S, only the respective S-wave components of the I 2S is reflected, di via the condenser lens 1 7, silicon down Dorikarurenzu 1 8 It is incident on tech evening 16.
- a component obtained by projecting the laser beam I 1S on the S-axis (hereinafter, referred to as a light component I 1S ) and a component obtained by projecting the laser beam I 23 on the S-axis Component (hereinafter referred to as light component I2S ) is incident on the detector 16 o
- the light receiving area of the detail 16 is divided into a plurality of areas, for example, as shown in FIG. 6, is divided into four areas 16a, 16b, 16c, and 16d. These split arrangement the level of the optical component I 1S detected by the region 1 6 b, 1 6 c, is so that arrangement to detect the level of light component I 2S by region 1 6 a, 1 6 d.
- the level signals detected in the areas 16a, 16b, 16c, and 16d of the detector 16 are level signals A, B, C, and D, respectively, the areas 16a, 1 6d From the level signal (A + D) detected by both, the difference between the level signal (B + C) detected in both of the regions 16b and 16c is obtained.
- a signal defined by the following equation with a value proportional to zero angular displacement due to the electro-optical Kerr effect can be obtained by the "Push-Pull method".
- MO signal reproduction signal obtained by reproducing information recorded on the magneto-optical disc 1 (hereinafter, referred to as MO signal), can be obtained by the following formula 1 it can.
- the first divided region 1 of the half-wave plate 15 out of the light emitted from the laser light source 11 is used. 5
- the light passed through a is radiated to the recording surface 1a of the magneto-optical disk 1 via the objective lens 13 and the reflected light therefrom is passed through the objective lens 13 to the 1Z2 wavelength plate 1
- the light passes through the second divided area 15 b of FIG. 5 and is incident on the detector 16 via the condenser lens 17 and the cylindrical lens 18.
- the light emitted from the laser light source 11 and passing through the second divided area 15 b of the 1 Z2 wavelength plate 15 the light emitted from the laser light source 11 is transmitted through the objective lens 13 to the magneto-optical disc.
- the recording surface 1 a of the laser 1 is irradiated with the reflected light, and the reflected light passes through the first divided area 15 a of the half-wave plate 15, and is separated by the polarization beam splitter 14.
- the light is incident on the detector 16 via the cylindrical lens 18.
- the detector 16 can detect the MO signal defined by Eq.
- optical pickup device for a magneto-optical storage device as the first embodiment of the present invention and the above-described conventional optical pickup device for a magneto-optical storage device.
- the reflectance of the polarization beam splitter for the P-wave component had to be set so that the amount of light incident on the detector and the noise were balanced.
- the reflectance of the polarization beam splitter 14 with respect to the P-wave component can be practically 0%, that is, the so-called coupling efficiency on the outward path can be approximately 100%, and the high power can be obtained. Pringing efficiency can be obtained.
- the output power as used in compact disk (CD) devices, etc. is low.
- Any laser diode can be used for the optical pickup device for the magneto-optical storage device of the present invention.
- the light amount of the P-wave component and the S-wave component of the laser beam that has passed through the 12-wavelength plate 15 twice is approximately 50% of the emitted light. By doing so, it is possible to reduce the influence of birefringence.
- 1 to 2 wave plate 1 5 have contact to the region 1 5 a and the region 1 5 b as described above, to form at different inclination of the d-axis and C 2 axis together
- the M0 signal may be affected by the boundary between the region 15a and the region 15b, but as shown in Fig. 6, make sure that the detector 16 does not detect the part corresponding to the boundary. By doing so, there is no impact.
- the focus error signal FE can be calculated by the following equation 2 using the astigmatism method J.
- the optical pickup device of this embodiment is a read-only type, It is possible to have a simple configuration substantially similar to an optical pick-up device for a write-once type optical disk or the like. That is, the configuration can be simpler than that of the conventional optical pickup device for a magneto-optical storage device.
- the configuration of the above-described 12-wavelength plate 15 and detector 16 is not limited to the configuration shown in FIG. 1.
- the 12-wavelength plate 15 may be disposed in close contact with the corresponding surface of the polarizing beam splitter 14 to detect the MO signal without using the condenser lens 17.
- FIG. 8 is a plan view of an optical pickup device for a magneto-optical storage device as a first modified example of the configuration of the optical pickup device of the first embodiment shown in FIG.
- the optical pick-up device shown in Fig. 8 consists of a laser light source 11, a collimator lens 12, a polarizing beam splitter 14, a 1Z two-wave plate 15, a detector 19 with a large light-receiving area, and an objective lens. 1 has 3 0
- the optical pickup device shown in Fig. 8 Comparing the optical pickup device shown in Fig. 8 with the optical pickup device shown in Fig. 1, the optical pickup device shown in Fig. 8 shows that the polarization beam splitter 14 and the objective lens 13 The interval is getting shorter. Further, the optical pickup device shown in FIG. 8 does not require the condenser lens 17 and the cylindrical lens 18. As a result, the optical pickup device shown in Fig. 8 is better than the optical pickup device shown in Fig. 1. It becomes even smaller.
- the laser light source 11A is, for example, F
- a hologram-equipped laser unit with a 0 CUS error detection function is used.
- the configuration of the 1-dual-wavelength plate 15 is such that the laser beam passes through the 12-wavelength plate 15 twice, assuming that there is no electro-optical force effect, as shown in FIG. beam
- the 12-wave plate 1 angle ⁇ with respect to the second region 1 5 b C 2 axes P axis of the 5 can be obtained by equation 3 below.
- the polarization beam splitter that makes the phase difference between the P wave and the S wave almost 0 degree can be easily obtained. I can make it.
- FIG. 11 shows a second modification of the first embodiment of the present invention in which the polarizing beam splitter 14A thus formed is arranged in the divergent light (or convergent light) of the laser light source 11.
- FIG. 3 is a plan view of an optical pickup device.
- the optical pickup device shown in FIG. 11 is composed of a laser light source 11, a 1-two-wavelength plate 15A formed as shown in FIG. 10, and a polarization beam splitter 14A having almost zero phase difference. , An objective lens 13, a condenser lens 17, a cylindrical lens 18 and a detector 16.
- a comparison of the optical pickup device shown in FIG. 11 with the optical pickup device shown in FIG. 1 shows that the optical pickup device shown in FIG. 11 has a collimating lens in the optical pickup device shown in FIG. 1 2 can be eliminated, and the optical pick-up device can be further miniaturized.
- the M 0 signal is generated by the electro-optical Kerr effect. SZN can be detected using almost 100% of wave components, and SZN can be considerably improved compared to conventional optical pickup equipment.
- the beta 2 approximately 0 degrees and, as illustrated in FIG. 1 2
- a single photoelectric conversion element (detector) whose signal receiving surface is not divided, for example, an avalanche photodiode (APD) 16 ⁇ Etc. may be used.
- APD avalanche photodiode
- the laser light source 11 is rotated slightly around the optical axis 0-0 ', that is, the light emitted from the laser light source 11 has a small amount of S-wave components, and this S-wave component is polarized beam split.
- the laser beam is taken out in the opposite direction (left side in the drawing) to the detector 16 shown in Fig. 11 or the APD 16 A shown in Fig. 12.
- ⁇ One-way control (FAPC) may be performed. In this case, since the emitted light from the laser light source 11 that passes through the polarized beam splitter 14A is only the P component, there is no effect on the detection of the M0 signal.
- FAPC One-way control
- this optical pickup device has a laser coupler 20 in which a laser light source, a polarized beam splitter, a detector, and the like are provided on the same silicon substrate, and a laser coupler 20 from the laser coupler 20.
- the objective lens 33 that irradiates the recording surface 1a of the optical disk 1 and the laser optical disk 1 between the laser cutter 20 and the magneto-optical disk 1 are divided into at least two on a plane perpendicular to the optical axis 0-0 '. constituted by the regions 3 4 a, 3 4 b have Keru your these areas C i-axis and C 2 axis and the different angles of 1/2-wavelength plate 3 4 that is.
- the laser coupler 20 includes a laser light source 22 provided on a silicon substrate 21, and an optical axis 0-between the laser light source 22 and the objective lens 33. It has a polarization plane disposed along 0 ′, and separates a predetermined polarization component of the reflected light from the recording surface 1a of the magneto-optical disk 1 and generates a focus error signal FE.
- a micro prism 23 and detectors 24 and 25 formed on the silicon substrate 21 and detecting light amounts at the same distance from the focal point.
- the light receiving areas of the detectors 24 and 25 include three areas 24 a, 24 b and 24 c and three areas 25 a and 25 b, respectively. It is divided into 25c.
- the optical pickup device shown in FIG. 13 also has the half-wave plate 34 placed on the optical axis 0-0 ′ similarly to the above-described embodiments shown in FIGS. 1, 8, 11, and 12.
- perpendicular (orthogonal) at least 2 divided on a plane, for example, when two divided regions 3 4 a, 3 axis and C 2 axis and the different angles at 4 b
- the reflectivity of the surface 23 a of the microprism 23 to the P wave and the S wave is set to 0% and 100%, respectively, and the half wavelength of the light emitted from the laser light source 22 is used.
- the reflected light passing through the first area 34 a of the plate 34 and reflected by the recording surface 1 a of the magneto-optical disk 1 passes through the second area 34 b of the half-wave plate 34, Of the light emitted from the laser light source 2 2, the reflected light that has passed through the ⁇ 2 area 3 4 b of the 12-wavelength plate 3 4 and reflected by the recording surface 1 a of the magneto-optical disk 1 is a half-wavelength plate.
- the regions 24 a, 24 b, 24 c of the detectors 24, 25 and the regions 25 a, 25 b, 25 are detected.
- the MO signal can be obtained by the following equation 4
- the focus error signal FE is obtained by the “microprism” detector focus error detection.
- j three Using dynamic amplifier 2 6, 2 7, 2 8, can be obtained by the following equation 5.
- the optical pickup device has a configuration in which the collimating lens 12 in the optical pickup device of the embodiment shown in FIGS. 1 and 8 is omitted, and the optical pickup device is further downsized.
- the optical pickup device shown in FIG. 8 is combined with the optical pickup device shown in FIG. 11, FIG. 12, or FIG. Can be configured.
- the optical pickup device as a fourth modification of the first embodiment of the optical pickup device for a magneto-optical storage device of the present invention illustrated in FIG. 16 is a collimating device in the optical pickup device illustrated in FIG. Evening lens 12 and objective lens 13 have been deleted, and condenser lens 17 and cylindrical lens 18 have been deleted. Therefore, as compared with the optical pickup device shown in FIG. 1, the length in the direction of the optical axis 0-0 'and the length orthogonal to the optical axis 0-0' are greatly shortened. The size of the pump device can be reduced.
- optical pickup device as the first embodiment of the present invention is not limited to the configuration illustrated in FIG. 16, and the configurations in FIGS. 1, 8, 11, 12, and 13 are appropriately selected. Any configuration can be combined.
- the polarizing beam splitter 14 is used.
- the optical axis of the S-wave component separated by the surface 23a of the microprism 23 is set to the direction (diameter or radius) of the magneto-optical disk 1, but the optical axis of this S-wave component is
- the optical pickup device may be arranged so as to be in the tangential direction of the track No. 1 and the M0 signal may be detected by the “evening 'push' pull method”.
- the present invention can be applied to various beam spot control methods in an optical pickup device, for example, an optical pickup device using a “three-beam method”.
- An optical pickup device for a magneto-optical storage device according to the present invention
- optical pickup device according to the second embodiment will be described with reference to FIGS.
- FIG. 17 is a plan view of an optical pickup device as a second embodiment of the optical pickup device for a magneto-optical storage device of the present invention.
- This optical pickup device consists of a laser light source 11, a collimator lens 12, a polarizing beam splitter 14, a combination phase retardation prism (CPR) 39, an objective lens 13, and a condenser lens. 17, a cylindrical lens 18, and a detector 16.
- the optical pickup device shown in FIG. 17 uses a CPR 39 instead of the 1Z2 wave plate 15 of the optical pickup device shown in FIG.
- Other components are the same as those shown in FIG. However, the path of the optical axis 0-0 ′ differs depending on the use of CPR39.
- FIGS 18a to 18c illustrate the three forms of CPR39.
- the CPR 39 shown in FIG. 18a is obtained by depositing the phase difference generating thin film 41 on the reflecting surface 40a of the 45-degree prism 40, and the phase difference generating thin film 41
- the first retardation generating thin film 41a and the second retardation generating thin film 41b are substantially the same area, and are symmetrically mounted on both sides of the reflecting surface 40a in the vertical direction with the optical axis 0-0 'as the center.
- phase difference generating thin films 4 1 a and 4 lb totally reflect the incident light, but the first phase difference generating thin film 41 a reflects the incident light without changing the phase, and the second The phase difference generating thin film 41b reflects incident light with a delay of 180 degrees. Such a phase delay can be performed by adjusting the film thickness of these phase difference generating thin films 41a and 41b.
- a phase difference of 180 degrees occurs between the light incident on the first phase difference generating thin film 41a and the light incident on the second phase difference generating thin film 41b.
- the CPR 39 performs the same function as the half-wave plate 15 shown in FIG.
- Figures 18b and 18c show other configurations of CPR39A and 39B.
- the CPR 39 A shown in Fig. 18b is composed of the first 'phase difference generating thin film 41 aA and the second phase difference generating thin film b A is applied. These films are formed such that a phase difference of 180 degrees occurs between the first retardation generating thin film 41 aA and the second retardation generating thin film 41 bA.
- the CPR 39 B shown in Fig. 18c is composed of a first phase difference thin film 41aB and a second phase difference thin film as total reflection films, each of the upper and lower halves of the reflecting surface 40a. 4 1 b B It is a thing. These films are formed such that a phase difference of 180 degrees occurs between the first phase difference generating thin film 41aB and the second phase difference generating thin film 41bB.
- any of the CPR 39, 39 A, and 39 B illustrated in FIGS. 18 a to 18 c may be used.
- the case where CPR 39 illustrated in a is used will be exemplified.
- FIG. 19 is a diagram illustrating the ray trajectory around the CPR 39 in FIG.
- Equations 1, 2, 4, and 5 hold true in the second embodiment.
- FIGS. 20a to 20d are graphs showing the characteristics of the lights L1 to L4.
- the polarization plane of the light L1 is inclined at an angle.
- the C axis of the 12-wavelength plate 15, that is, , C i-axis and C 2 axis is P direction.
- the light is irradiated onto the recording surface 1a of the magneto-optical disk 1 via the objective lens 13 and the reflected light is reflected and the optical path is inverted.
- the phase shifts by the angle + k due to the electro-optical Kerr effect.
- the return light L 3 is reflected by the first phase difference generating thin film 41 a, so that the phase is shifted 90 degrees.
- the hemisphere area is
- the same result as that of the first embodiment is obtained in the second embodiment. Signal can be detected.
- the optical pickup device of the first embodiment using the 1Z2 wavelength plate 15 shown in FIG. 1 is compared with the optical pickup device of the second embodiment using the CPR39.
- the half-wave plate 15 is composed of a first half-wave plate 15a and a second 1Z two-wave plate 15b which are divided into two optical axes. Tensions around 0—0 '(as boundaries) It is manufactured together, but in practice it is difficult to manufacture precisely and is not always suitable for mass production.
- the CPR 39 only requires the 45 ° mirror 40 to be coated with the phase difference generating thin film 41, so it can be easily manufactured and has excellent mass productivity.
- CP R39 has the advantage that the degree of vectorial interference can be set arbitrarily at the angle ⁇ shown in Figs. 20a to 20d.
- detection can be performed at twice the angle, so that the detection sensitivity is increased.
- the optical axis 0-0 ′ is deflected by the CPR 39, and the distance between the laser light source 11 and the objective lens 13 is increased. Can be made smaller. That is, the optical pickup device of the second embodiment has an advantage that the optical system can be reduced in size.
- CPR 39 can also be manufactured at low cost.
- the reflected return light is polarized in the same direction, but only the ⁇ signal is obtained in the opposite phase.
- a phase difference generator that generates a predetermined phase difference between one light incident on the phase difference generating thin film 41a and the other light incident on the second phase difference generating thin film 41b. Can be used for a wide range of applications.
- This phase difference generating device can arbitrarily change the phase difference depending on the film thickness of the phase difference generating thin film 41 adhered to the reflecting surface 40a of the 45 degree prism 40.
- phase difference generating thin film 41 As a method of applying the phase difference generating thin film 41, various methods such as sputtering can be used depending on the material of the phase difference generating thin film 41.
- the modification described as the first embodiment can be applied to the optical pickup device of the second embodiment.
- FIG. 21 shows a first modification of the second optical pickup device, in which a polarizing beam splitter 14 corresponding to FIG. 7 and a detector 19 having a large light receiving area are integrated.
- FIG. 21 shows the half-wave plate 15 shown in FIG. 7 as the polarizing beam splitter 1. 4 has not arrived. It goes without saying that the polarization beam splitter 14 shown in FIG. 21 and the detector 19 having a large light receiving area can be applied to the optical pickup device shown in FIG.
- the condenser lens 17 shown in FIG. In addition, the cylindrical lens 18 becomes unnecessary.
- the configuration corresponding to FIGS. 11 and 12 that is, the configuration of the laser light source 11 and the polarization beam splitter 14A is shown. It is possible to adopt a configuration in which the collimation lens 12 between them is deleted.
- the advantages of the second modification are the same as those of the optical pickup device shown in FIGS. 11 and 12. Illustration of this configuration is omitted.
- a configuration corresponding to FIG. 13 can be employed as a third modification of the optical pickup device according to the second embodiment of the present invention.
- the advantages of the third modification are the same as the advantages of the optical pick-up device shown in FIG. Illustration of this configuration is also omitted.
- An optical pickup device for a magneto-optical storage device according to the present invention
- FIG. 22 is a plan view of an optical pickup device according to a third embodiment.
- This optical pickup device consists of a laser light source 11, a collimator lens 12, a polarizing beam splitter 14, an optical rotation plate 52, an objective lens 13, a condenser lens 17, and a cylindrical lens. It consists of 18 and 16 detectors.
- the optical pickup device shown in FIG. 22 is different from the optical pickup device shown in FIG. 1 in that an optical rotation plate 52 is used instead of the 1 Z 2 wavelength plate 15 shown in FIG.
- the basic configuration and other components are the same as those of the optical pickup device shown in Fig. 1.
- the optical rotation plate 52 includes a left optical rotation plate 52a and a right optical rotation plate 52b.
- the left-handed rotating plate 52 a rotates only the polarized light by a predetermined angle counterclockwise when viewed from the observation side, that is, the objective lens 13 side in this example (the same applies hereinafter) without changing the phase difference.
- the right-handed rotation plate 52b rotates only polarized light by a predetermined angle clockwise when viewed from the observation side without changing the phase difference.
- the left optical rotation plate 52a and the right optical rotation plate 52b do not impart an optical phase difference (ratio) to the transmitted light, they are rotated with linear polarization. Rotational power changes even when wavelength changes It just works. Therefore, the light incident on the left optical rotation plate 52a and the light incident on the right optical rotation plate 52b have an optical rotation angle difference by the sum of the optical rotation angles of the two.
- FIGS. 23A and 23B illustrate a method of manufacturing the optical rotation plate 52.
- an optical member 55 having a thick right-handed rotation angle having a thickness t 0 and an optical member 54 having a left-handed rotation angle having substantially the same thickness have an optical axis 0-.
- the surface is centered on the plane corresponding to 0 '. Since the thickness of these optical members 54 and 55 is large, this work for imposition can be easily performed.
- the optical members 54 and 55 for example, a crystal in which quartz is pressed perpendicular to the optical axis is used, and the right crystal has an optical rotation angle of the right crystal 55, and the left crystal has an optical rotation angle of the left. Used as optical member 54.
- the rotation angle is determined by the thickness t of the optical member.
- the optical members 54 and 55 having a thickness of t0 are polished from both sides in a state where the optical members 54 and 55 are imposed, thereby manufacturing an optical rotation plate 52 having a desired thickness t.
- the desired thickness t is, for example, about 3.7 mm for an optical rotation angle of 45 degrees. Polish until the specified thickness t according to the desired rotation angle. This polishing operation can also be facilitated. Therefore, the optical rotation plate 52 on which the left optical rotation plate 52a and the right optical rotation plate 52b are imposed can be easily manufactured, and can be manufactured at low cost and in a short time. Moreover, the angle of rotation can be set arbitrarily by adjusting the thickness. The angle of rotation is almost proportional to its thickness.
- the composite optical rotation plate 52 When the CRP used in the third embodiment of the present invention, that is, the composite optical rotation plate 52 is compared with the CPR 39 of the second embodiment, when the composite optical rotation plate 52 is used, as is because there is no axis and C 2 axis, such as a 1-wavelength plate 1 5 in a plane, rather it may also be allowed to be incident toward the linearly polarized light in any direction in the plane, shown in FIG. 2 0 a Since there is no need to specify the polarization angle of the incident light, design flexibility is increased.
- the optical rotation plate 52 formed by combining the two left optical rotation plates 52 a and the right optical rotation plate 52 formed in this way is called a composite optical rotation plate (Combination Rotating Ptate: CRP).
- CRP Composite Rotating Ptate
- FIG. 24a is a front view of the CRP used in the third embodiment of the present invention
- FIG. 24b is a top plan view thereof.
- the figures in the drawings indicate actual dimensions in mm.
- the processing accuracy was ⁇ 0.1 mm.
- the clear aperture shaded to indicate the effective light transmission area is 7 mm x 7 mm.
- wavelength 780 ⁇ 20 nm
- transmitted wavefront or less
- Optical axis sunset No offset between the transmitted light of the left and right rotator plates 52a, 52b, pils (small cracks), cracks in the clear aperture in the overview inspection The one without scratches, scratches, etc. was used. For convenience, those having the following optical rotation angles were used as model names shown in Table 2 below. Table 2
- FIGS. 25 and 26 are perspective views of the optical pickup device illustrated in FIG. However, the direction of the incident light from the laser light source 11 and the collimating lens 12 to the polarizing beam splitter 14 is incident on the polarizing beam splitter 14, and the light from the polarizing beam splitter 14 is emitted from the detector 16 Orientation is different from Fig. 22.
- FIG. 25 shows the conversion of the polarization plane of I 1
- FIG. 26 shows the conversion of the polarization plane of I 2.
- the directions of the arrows in the circles indicate the directions of the linearly polarized light.
- the laser beam It which is the S-polarized light from the collimating lens 12, is reflected 100% by the polarizing beam splitter 14 and passes through the left optical rotation plate 52 a.
- the laser beam I u is obtained by rotating the plane of polarization by +.
- this laser beam I passes through the objective lens 13, is reflected by the recording surface 1 a of the magneto-optical disk 1, and passes through the objective lens 13 again, the return light is transmitted to the center axis (optical axis) of the objective lens 13.
- the laser beam I 12 passes through the optical path on the opposite side with respect to (0-0 ′).
- the polarization plane at this time remains +.
- the laser beam I i 2 passes through the right-handed rotating plate 52b, a clockwise rotation is given.
- IL 3 is the laser beam incident on the left optically rotating plate 52a. Is rotated by +2 with respect to. That is, the incident light I t and the emitted light I 13 on the optical rotation plate 52 have a total rotation angle of + 2 ⁇ .
- the laser beam I is subjected to polarization detection at the polarization beam splitter 14, and only the P-wave component is transmitted, and the laser beam I 1S enters the detector 16.
- the amplitude of the laser beam I 1 S incident on the detector 16 has a value represented by the following equation 6.
- the conversion of the polarization plane of the optical path I2 shown in FIG. 26 is also basically the same as described above.
- the laser beam I 2, which is S-polarized light from the collimating lens 12, is reflected 100% by the polarizing beam splitter 14, and the right-handed rotator plate 5 b on the opposite side of the laser beam It when passing through a serving as a laser beam I 21 polarization plane has been found rotated by Ichihi reversed.
- I isx sin (+ 2 + 0 k )
- the MO signal is obtained by differential detection of the signals obtained from PD 1 and PD 2 of the detector 16.
- FIG. 27 is a diagram illustrating the detection of the MO signal by the area differential method (Double Cross Section Differential Detection Method).
- the area differential method is a single laser beam, but its cross section has a semi-lunar area and a laser beam whose polarization is controlled independently. This is named because it means that the M0 signal can be detected.
- both the laser beams I 1S and I 2S have the same S polarization component only.
- the k component is detected as a difference in light intensity, and when the two signals are differentiated, the in-phase component is removed.
- the polarization beam splitting is performed. Since the common mode rejection can be performed up to the extinction ratio of 14 in the evening, a high quality desired M0 signal with a high common mode rejection ratio can be obtained.
- the detection of the M0 signal can be performed by a process similar to taking the push-pull.
- the M0 signal detection system can be configured with a planar configuration, so that the optical pickup device can be downsized.
- the MO signal can be detected by the sum of the four divided signals of the MO signal detector 16 and the RF signal, that is, with almost the same configuration as the CD optical system.
- the light quantity is detected only in the return light path from the recording surface 1a, and the light quantity in the outward path is substantially transmitted by 100%. It is above.
- the optical rotation angle of the composite optical rotation plate 52 can be arbitrarily set without affecting the power pulling efficiency on the outward path, the amount of light incident on the detector 16 can be controlled.
- the rotation angle between the left-handed rotation plate 52a and the right-handed rotation plate 52b is deviated from 0 to 45.
- the return light to the detector 16 can be arbitrarily set from 0 to 100%.
- the angle of rotation of the convoluted light plate 52 the return light can be set arbitrarily, so that the detector 16 can be given a degree of freedom in the design of the amplifier connected to the output side, thereby improving the SN.
- the phase difference does not change as in the case of the 12-wavelength plate 15
- the variation in the oscillation wavelength of the laser light source 11 does not matter.
- two or more laser light sources 11 can be assembled with the same optical system.
- the polarization beam splitter 14 is less expensive than the beam splitter for MO, and the composite optical rotation plate 52 is also less expensive than the Wollaston prism.
- the optical pick-up device of the present invention is configured as illustrated in FIG.
- FIG. 28 corresponds to FIG. 13 illustrating the configuration of an optical pickup device using the 12-wavelength plate 15 as the first embodiment.
- the optical pickup device shown in FIG. 28 does not include the 12-wavelength plate 15, and the composite optical rotation plate as shown in FIG. 5 2 and the polarizing beam splitter 14 and the detector 16
- An integrated optical assembly 60 is provided above the surface 14a of the polarizing beam splitter 14, a laser coupler 20 similar to the one illustrated in FIG. 14 is provided.
- a silicon mirror 32 is disposed on the optical assembly 60, and an objective lens 13 is disposed above the silicon mirror 32.
- the advantages of configuring a super-resolution optical system, the effect of canceling the push-pull signal to the MO, and the power-off of the MTF (Modulation on Trnsfer Function) are reduced only by the common-mode noise. New effects were found, such as the effect that can be reduced by half. These details will be described in detail as a fourth embodiment.
- the above-described composite optical rotation plate 52 is used not only for the optical pickup device for the magneto-optical storage device of the present invention, but also for changing the phase of light in addition to the CPR 39 described in the second embodiment. Therefore, the present invention can be applied to various uses for generating a phase difference between a plurality of lights.
- An optical pickup device for a magneto-optical storage device according to the present invention
- the internal polarization state of the composite optical rotation plate 52 is converted and the MO signal is thereby detected.
- the optical characteristics are expressed by, for example, an MO signal, a phase pit signal, a pre-group signal, and the like.
- the change of the spatial frequency axis (MTF) is described.
- FIGS. 30 and 31 are schematic diagrams of the optical system of the optical pickup device of the fourth embodiment.
- FIG. 30 shows the outward route
- FIG. 31 shows the return route.
- This optical pick-up device uses a composite optical rotation plate 62 instead of the composite optical rotation plate 52 of the optical pickup device shown in FIG. 22 of the third embodiment or shown in FIGS.
- a beam splitter 64 is provided between the evening lens 12 and the polarizing beam splitter 14, and a second detector 66 is provided on the exit side of the beam splitter 64.
- the laser light source 11, the collimating lens 12, the polarizing beam splitter 14, the objective lens 13, and the magneto-optical disk 1 (recording surface 1a) It is the same as the pick-up device.
- the beam in the composite optical rotation plate 62 is a semi-moon-shaped split region
- the beam spot obtained by converging these beams with a lens is different from a normal beam spot.
- the polarization state of the light beam immediately before entering the objective lens 13 is the half-moon-shaped left-handed rotation plate 6 2 a and right-handed rotation plate of the compound optical rotation plate 62. Since there is a difference in angle + ⁇ and one polarization in each cross section of 62b, the same polarization components interfere with each other in the beam spot.
- the direction along the dividing line 62 0 of the composite optical rotation plate 62 is defined as the X direction, and the direction orthogonal to the dividing line 62 0 is defined as the y direction.
- Figures 34a and 34b show the results of a simulation of how the beam spots are made for each component. From this, it is possible to obtain a beam spot of the y component, which has the same polarization direction as that of the beam spot of the in-phase component, that is, the so-called in-phase component, but has the phase inverted. Since the beam spot of the component in the y direction has a 180 ° phase inversion at the center of the beam, the light intensity is always zero.
- the optical rotation angle ⁇ of the composite optical rotation plate 62 is large.
- the y component shown in Figs. 34a and 34b increases, and as shown in Figs. 32a to 32e, the composite optical rotation plate 62
- the beam spot in the split direction of 2 widens the field.
- bi one Mus pots becomes bi one beam light shape itself of the y component E 7.
- the energy distribution of this beam spot is important.
- PSF Point Spread Fucction
- the MTF and other parameters can be determined.
- the composite optical rotation plate 6 2 it has a different PSF respectively from the E x formed minutes E 7 components.
- the MO signal can be obtained by the area differential method.
- the dividing line 62 of the compound optical rotation plate 62 is arranged in parallel with the pre-group of the recording surface 1a, and An experiment was conducted on the case where the left-handed rotating plate 62a and the right-handed rotating plate 62b were divided, and it was confirmed that the MO signal was output and that there was an effect of removing the push-pull signal. The details will be described with reference to FIGS. 36a to 36m.
- 3 6 a to view 3 6 g, 3 6 h shows the respective beam state in the position of the backward I 12, I 22, shown in FIG 1.
- FIG. 36 a Referring to FIG. 30 and FIG. 31, the entire polarization plane of the laser beam reflected by the polarization beam splitter 14 is in the S direction. The amplitude at this time is normalized to 1. The reflectance of the recording surface 1a of the magneto-optical disk 1 is also assumed to be 1.
- Figure 3 6 b through the composite optical rotation plate 6 2, the laser beam reflected by the recording surface 1 a and I 22, I 12. ,
- Figure 3 6 c and FIG 3 6 d consider separately the beam E x component and E y component. Then, it is assumed that these beams undergo S-axis diffraction on the recording surface 1a. To facilitate understanding, the pre-group is considered in the spatial frequency domain above ⁇ / ⁇ (numerical aperture) where the push-pull is maximized.
- Fig. 36e and Fig. 36f The (+/-) first-order diffracted light and zero-order light overlap due to the pre-group. (+ Z—) Let the intensities of the first-order diffracted light be ⁇ and r, and let the intensity of the zero-order light be c. (+/-) The first-order diffracted light is diffracted by a factor of ⁇ and r times, including the plane of polarization, so that in Fig. 36f, the phase overlaps with the 0th-order light and has an opposite phase.
- Figures 36 g and 36 h Figures 36 e and 36 The solution was shown in amplitude.
- Figure 3 6 i and 3 6 j shows a state at each position of the outward-bi one beam I 13, I 23, shown in FIG. 3 0.
- Figure 36i and Figure 36j In the process of returning the light reflected from the recording surface 1a, the light again passes through the composite optical rotation plate 62, and the polarization shown in Figure 36g and Figure 36h together with the beam shown in Figure 36h Since the surface is rotated by the rotation angle ⁇ , the ⁇ ⁇ component and the E y component are mixed again.
- FIG. 36k and FIG. 36 ⁇ show the states at the respective positions of the beams I 1SA and I 2SA on the outward path shown in FIG.
- Fig. 36k and Fig. 36_ ⁇ The components shown in Fig. 36i and Fig. 36j are detected by the polarization beam splitter 14, and only the P component is transmitted.
- Figure 36m Add the P components shown in Figure 36k and Figure 36j ?.
- both the beams I 1SA and I 2SA are 2 c ⁇ si ⁇ ⁇ ⁇ cos
- the push-pull signal is 0, and the phase grub diffracted light is independent of the magnifications ⁇ , r, and C, and
- the S component in FIGS. 36 i and 36 j is reflected by the polarizing beam splitter 14, and this polarized light depends on the magnifications ⁇ , r, and c. And the push-pull component is included because it depends on the angle of rotation. Therefore, a tracking servo can be applied with a signal from the second detector 66.
- the beams I 1SA and I 2SA have the same plane of polarization, but the phase is 180 . Because there is, it is possible to detect the MO signal from (I 1SA -I 2SA ).
- the signal from the detector 16 is radially divided.
- a push-pull signal can be extracted by the push-pull method, and an MO signal can also be extracted by subtracting a signal that depends on the optical rotation plate in the tangential direction.
- FIGS. 38a to 38i are line trajectories corresponding to FIGS. 36a to 36m for the optical system shown in FIG.
- the composite optical rotation plate 62 or the composite optical rotation plate 72 depends on the optical rotation angle a and the division direction of the tangential direction or the radial direction to obtain the MO signal and It has the characteristic that the appearance of the pit signal is different.
- Fig. 39a and Fig. 39 b are respectively
- FIG. 6 is a characteristic diagram of a differential (push-pull) signal and a sum (R F) signal based on a simulation-based simulation at 45 ° and 45 °.
- the horizontal axis indicates ⁇ .
- Fig. 39b shows that when the compound optical rotation plate 72 is divided in the tangential direction as illustrated in Fig. 37, the MTF of the pit row aligned in the tangential direction can be reproduced only at about half the spatial frequency. Is not shown.
- the absolute value of the composite optical rotator 72 varies depending on the angle of rotation ⁇ of the rotator plate 72.
- the MO signal can be reproduced by changing the shape of the MTF curve.
- PBS 45 The maximum amplitude can be obtained because it is detected by.
- Figure 41a shows the curve of the theoretical value of the MO signal
- Figure 41b shows the curve of the measured value.
- the theoretical value and the measured value correspond well.
- FIG. 42 is a graph in which the values of FIG. 41 a and FIG. 41 b have been normalized to 1.0 to form an MTF curve.
- Curve CV 11 is the common-mode noise, that is, the RF signal
- the above described composite optical rotation plate 62 of the fourth embodiment of the present invention can be applied as an optical pickup device in the same manner as in FIGS. 28 and 29 shown as the third embodiment.
- composite optical rotation plate 62 or the composite optical rotation plate 72 described as the fourth embodiment of the present invention can be used for other optical devices other than the optical pickup device.
- the present invention is not limited to the above-described embodiment, but may take various other modified forms.
- the optical pickup device for a magneto-optical storage device of the present invention can be suitably used for an optical recording / reproducing device.
- the optical pickup device for a magneto-optical storage device of the present invention is configured to be small, the entire magneto-optical storage device incorporating this optical pickup device for a magneto-optical storage device can also be miniaturized.
- the optical pickup device for a magneto-optical storage device of the present invention can be applied to a small-sized magneto-optical storage device.
- the ⁇ wavelength plate, the combination phase delay prism, and the composite optical rotation plate exemplified as the elements constituting the optical pickup device for the magneto-optical storage device of the present invention can be applied to the optical pickup device for the magneto-optical storage device.
- the present invention can be applied to various devices that change the phase of two beams in a predetermined relationship.
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- Physics & Mathematics (AREA)
- Optics & Photonics (AREA)
- General Physics & Mathematics (AREA)
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Description
Claims
Priority Applications (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP51041393A JP3658763B2 (ja) | 1992-02-07 | 1993-02-08 | 光磁気記憶装置用光ピックアップ装置 |
EP93903326A EP0579843B1 (en) | 1992-02-07 | 1993-02-08 | Optical pickup apparatus for magneto-optical storage |
DE69327369T DE69327369T2 (de) | 1992-02-07 | 1993-02-08 | Optisches abtastgerät für eine magneto-optische speicherung |
US08/122,411 US5577018A (en) | 1992-02-07 | 1993-02-08 | Phase changing apparatus and optical pickup apparatus for magneto-optic storage device using same |
Applications Claiming Priority (4)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
JP5694592 | 1992-02-07 | ||
JP4/56945 | 1992-02-07 | ||
JP4/137769 | 1992-04-30 | ||
JP13776992 | 1992-04-30 |
Publications (1)
Publication Number | Publication Date |
---|---|
WO1993016469A1 true WO1993016469A1 (en) | 1993-08-19 |
Family
ID=26397950
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
PCT/JP1993/000158 WO1993016469A1 (en) | 1992-02-07 | 1993-02-08 | Phase varying device, and optical pickup apparatus using the same for magneto-optical storage |
Country Status (5)
Country | Link |
---|---|
US (3) | US5577018A (ja) |
EP (1) | EP0579843B1 (ja) |
JP (1) | JP3658763B2 (ja) |
DE (1) | DE69327369T2 (ja) |
WO (1) | WO1993016469A1 (ja) |
Cited By (1)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0671734A1 (en) * | 1994-03-08 | 1995-09-13 | Sony Corporation | Optical device |
Families Citing this family (24)
Publication number | Priority date | Publication date | Assignee | Title |
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DE69327369T2 (de) * | 1992-02-07 | 2000-06-21 | Sony Corp | Optisches abtastgerät für eine magneto-optische speicherung |
DE69329945T2 (de) * | 1992-07-14 | 2001-06-07 | Seiko Epson Corp | Polarisierendes element, optisches element und optischer kopf |
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JP5173659B2 (ja) * | 2008-08-01 | 2013-04-03 | 三洋電機株式会社 | 光ピックアップ装置および光ディスク装置 |
JP5173953B2 (ja) * | 2008-08-01 | 2013-04-03 | 三洋電機株式会社 | 光ピックアップ装置および光ディスク装置 |
DE102011108181B4 (de) * | 2011-07-22 | 2015-02-26 | Bundesrepublik Deutschland, vertreten durch das Bundesministerium für Wirtschaft und Technologie, dieses vertreten durch den Präsidenten der Physikalisch-Technischen Bundesanstalt | Verfahren zum ortsaufgelösten Messen einer Magnetisierung einer magnetischen Struktur und magnetooptischer Datenspeicher |
CN103809708A (zh) | 2012-11-07 | 2014-05-21 | 辉达公司 | 平板电子设备及其辅助散热装置、以及两者的组件 |
Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5788540A (en) * | 1980-11-21 | 1982-06-02 | Olympus Optical Co Ltd | Method and apparatus for information read-in of optical magnetic recording medium |
JPS5979446A (ja) * | 1982-10-28 | 1984-05-08 | Sharp Corp | 磁気光学ヘッド |
JPS5996551A (ja) * | 1982-11-25 | 1984-06-04 | Sony Corp | 光磁気記録体再生装置 |
JPS59121637A (ja) * | 1982-12-28 | 1984-07-13 | Fujitsu Ltd | 磁気光学記録再生装置 |
JPS59191156A (ja) * | 1983-04-13 | 1984-10-30 | Nippon Kogaku Kk <Nikon> | 旋光子を設けた磁気光学再生装置 |
JPS6190346A (ja) * | 1984-10-11 | 1986-05-08 | Hitachi Ltd | 光磁気再生装置 |
JPS61160852A (ja) * | 1984-12-30 | 1986-07-21 | Olympus Optical Co Ltd | 光磁気ピツクアツプ装置 |
JPS6266452A (ja) * | 1985-09-19 | 1987-03-25 | Nec Corp | 光磁気ヘツド |
JPS63138533A (ja) * | 1986-11-28 | 1988-06-10 | Fujitsu Ltd | 光磁気デイスク装置の再生方式 |
JPS63200346A (ja) * | 1987-02-13 | 1988-08-18 | Nec Corp | 光磁気記録再生ヘツド |
JPS63247941A (ja) * | 1987-04-01 | 1988-10-14 | Nec Corp | 光磁気用光ヘツド装置 |
JPS63291238A (ja) * | 1987-05-21 | 1988-11-29 | Seiko Epson Corp | 光メモリ−装置 |
JPH01315036A (ja) * | 1988-03-18 | 1989-12-20 | Sony Corp | 光学ピツクアツプ装置 |
Family Cites Families (17)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
US4298244A (en) * | 1978-02-28 | 1981-11-03 | Ricoh Company, Ltd. | Information recording method and apparatus |
JPS57147148A (en) * | 1981-03-05 | 1982-09-10 | Olympus Optical Co Ltd | Information reproducer with magnetooptic system |
JPS5963040A (ja) * | 1982-09-16 | 1984-04-10 | Canon Inc | 光磁気情報読取装置 |
US4595261A (en) * | 1983-10-13 | 1986-06-17 | International Business Machines Corporation | Phase retardation element and prism for use in an optical data storage system |
US4858218A (en) * | 1984-09-12 | 1989-08-15 | Nikon Corporation | Optical recording medium and reproducing apparatus |
KR950005031B1 (ko) * | 1986-02-24 | 1995-05-17 | 소니 가부시끼가이샤 | 초점 검출 장치 |
US5270996A (en) * | 1986-12-25 | 1993-12-14 | Nec Corporation | Optical head with diffraction grating producing five diffracted detection light beams |
JPS63292432A (ja) * | 1987-05-25 | 1988-11-29 | Sony Corp | 光学ピックアップ装置 |
US4823220A (en) * | 1987-11-16 | 1989-04-18 | International Business Machines Corporation | Detector for magnetooptic recorders |
JPH0770065B2 (ja) * | 1988-04-20 | 1995-07-31 | シャープ株式会社 | 光ピックアップ装置 |
JPH01273238A (ja) * | 1988-04-25 | 1989-11-01 | Sony Corp | 光学ヘッド装置 |
EP0374841B1 (en) * | 1988-12-20 | 1994-03-09 | Nec Corporation | Optical head device for optimally detecting a focussing error |
JP2982965B2 (ja) * | 1989-09-18 | 1999-11-29 | オリンパス光学工業株式会社 | 光学式読み取り装置 |
JPH0460933A (ja) * | 1990-06-26 | 1992-02-26 | Matsushita Electric Ind Co Ltd | 光ピックアップヘッド装置 |
JPH0827962B2 (ja) * | 1990-06-27 | 1996-03-21 | パイオニア株式会社 | 光ピックアップ |
US5119352A (en) * | 1990-08-17 | 1992-06-02 | Hewlett-Packard Company | Magneto optic data storage read out apparatus and method |
DE69327369T2 (de) * | 1992-02-07 | 2000-06-21 | Sony Corp | Optisches abtastgerät für eine magneto-optische speicherung |
-
1993
- 1993-02-08 DE DE69327369T patent/DE69327369T2/de not_active Expired - Fee Related
- 1993-02-08 WO PCT/JP1993/000158 patent/WO1993016469A1/ja active IP Right Grant
- 1993-02-08 EP EP93903326A patent/EP0579843B1/en not_active Expired - Lifetime
- 1993-02-08 US US08/122,411 patent/US5577018A/en not_active Expired - Fee Related
- 1993-02-08 JP JP51041393A patent/JP3658763B2/ja not_active Expired - Fee Related
-
1995
- 1995-02-24 US US08/394,270 patent/US5563869A/en not_active Expired - Fee Related
-
1996
- 1996-07-24 US US08/685,474 patent/US5742577A/en not_active Expired - Fee Related
Patent Citations (13)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
JPS5788540A (en) * | 1980-11-21 | 1982-06-02 | Olympus Optical Co Ltd | Method and apparatus for information read-in of optical magnetic recording medium |
JPS5979446A (ja) * | 1982-10-28 | 1984-05-08 | Sharp Corp | 磁気光学ヘッド |
JPS5996551A (ja) * | 1982-11-25 | 1984-06-04 | Sony Corp | 光磁気記録体再生装置 |
JPS59121637A (ja) * | 1982-12-28 | 1984-07-13 | Fujitsu Ltd | 磁気光学記録再生装置 |
JPS59191156A (ja) * | 1983-04-13 | 1984-10-30 | Nippon Kogaku Kk <Nikon> | 旋光子を設けた磁気光学再生装置 |
JPS6190346A (ja) * | 1984-10-11 | 1986-05-08 | Hitachi Ltd | 光磁気再生装置 |
JPS61160852A (ja) * | 1984-12-30 | 1986-07-21 | Olympus Optical Co Ltd | 光磁気ピツクアツプ装置 |
JPS6266452A (ja) * | 1985-09-19 | 1987-03-25 | Nec Corp | 光磁気ヘツド |
JPS63138533A (ja) * | 1986-11-28 | 1988-06-10 | Fujitsu Ltd | 光磁気デイスク装置の再生方式 |
JPS63200346A (ja) * | 1987-02-13 | 1988-08-18 | Nec Corp | 光磁気記録再生ヘツド |
JPS63247941A (ja) * | 1987-04-01 | 1988-10-14 | Nec Corp | 光磁気用光ヘツド装置 |
JPS63291238A (ja) * | 1987-05-21 | 1988-11-29 | Seiko Epson Corp | 光メモリ−装置 |
JPH01315036A (ja) * | 1988-03-18 | 1989-12-20 | Sony Corp | 光学ピツクアツプ装置 |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
EP0671734A1 (en) * | 1994-03-08 | 1995-09-13 | Sony Corporation | Optical device |
US5568463A (en) * | 1994-03-08 | 1996-10-22 | Sony Corporation | Semiconductor laser device to detect a divided reflected light beam |
Also Published As
Publication number | Publication date |
---|---|
US5577018A (en) | 1996-11-19 |
US5742577A (en) | 1998-04-21 |
EP0579843A4 (en) | 1996-05-08 |
DE69327369T2 (de) | 2000-06-21 |
EP0579843B1 (en) | 1999-12-22 |
EP0579843A1 (en) | 1994-01-26 |
DE69327369D1 (de) | 2000-01-27 |
JP3658763B2 (ja) | 2005-06-08 |
US5563869A (en) | 1996-10-08 |
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