KR100388060B1 - Optical data storage device using solid immersion lens and waveguide grating coupler - Google Patents

Abstract

The present invention relates to an optical storage device using a SIL (Solid Immersion Lens) and a waveguide diffraction grating coupler, and more particularly, to an apparatus for increasing recording density and connection rate by using a head integrating a waveguide diffraction grating coupler and a SIL in an optical information storage device. It is about. To this end, the present invention provides an optical storage device capable of recording / reproducing information, comprising: a recording medium configured to rotate about a first rotating hub in a cartridge; An arm having one end fixed to a second rotating hub in the cartridge; A first optical waveguide provided along one surface of the arm from the second rotating hub; And a slide head connected to the first optical waveguide, wherein the slide head is installed on one surface of a flat body having an internal space and moves a second optical waveguide for moving the light received through the first optical waveguide. A plurality of diffraction gratings provided along the second optical waveguide to diffract the light transmitted along the second optical waveguide, and installed on the other surface of the inside of the planar body, and the light diffracted by the diffraction grating into one Solid Immersion Lense (SIL) focusing to focus, and a coil to generate a magnetic field around the SIL.

Therefore, since the optical storage device of the present invention uses a planar waveguide diffraction grating coupler, it is possible to obtain an ultra-compact and ultra-lightweight head, and thus to obtain a fast connection rate and to be incorporated in one cartridge. In addition, since the SIL-integrated head and the near field type and planar waveguide grating coupler are integrated in the cartridge, the cartridge is protected from contamination and high storage density can be obtained.

Description

Optical data storage device using solid immersion lens and waveguide grating coupler}

The present invention relates to an optical storage device using a SIL (Solid Immersion Lens) and a waveguide diffraction grating coupler, and more particularly, to an apparatus for increasing recording density and connection rate by using a head integrating a waveguide diffraction grating coupler and a SIL in an optical information storage device. It is about.

Optical data storage devices are being developed in order to obtain high recording density, transmission rate, fast connection rate, and smooth mobility.

In terms of recording density, DVD players currently commercially available can record and play back up to 4.7 G-bytes on a disc by using a multi-layer recording medium capable of storing information in multiple layers. However, the increasing demand for informatization has required mass storage of more than tens of G-Bytes, and many techniques for increasing the storage density have been proposed to realize this. Among them, near-field recording technology is strong, and near-field light storage technology is largely divided into aperture type and SIL.

In order to increase the recording density, the size of the light spot focused on the recording medium should be reduced, but the size of the focused light spot cannot be reduced below a certain size at a given wavelength due to the diffraction limit of light. Therefore, in order to solve this problem, the aperture method forms a small aperture below the diffraction limit, and closes the distance between the aperture and the recording medium to several tens of nm or less, and then passes the light through the aperture. The information is then stored using the transfer of light energy distribution in the aperture to the recording medium without being affected by diffraction as much as the aperture size. However, the aperture method transmits light through an opening of several tens of nm or less formed at the end of a pointed optical fiber coated with a metal film to store information, but the amount of light exiting the aperture is extremely small, so that the amount of light energy required for actual recording is absorbed. It is difficult to obtain.

On the other hand, the SIL method uses a principle that the wavelength is reduced when the light is focused into the medium having a high refractive index and the refractive angle is increased to focus the light inside the hemispherical SIL medium to reduce the size of the focused light spot below the diffraction limit.

In order to implement the above principle, the SIL method is configured such that light is focused on a plane inside the SIL medium by bringing the flat bottom surface of the SIL into proximity with the recording medium. The focused light forms light spots with short wavelengths and high NA (Numerical Aperture) due to the high refractive index of the SIL medium, and the energy of these light spots is transmitted on a very close recording medium with little influence of diffraction to record the information. do. In addition, in the SIL method, a method of mounting the SIL in a flying head, which is adopted in a conventional hard disk, has been proposed and studied in order to access and transmit information more quickly.

However, in order to increase the recording density in the apparatus applying the near field recording method using SIL to the slide head, it is necessary to prevent contamination of the recording surface and the joint surface between the SIL. In order to avoid contamination of the recording surface, it is best not to expose the optical storage head and the recording surface to air, but the conventionally proposed method has a limitation in increasing the recording density because the SIL and the storage medium are easily exposed to air and are contaminated. . In addition, since the mirror is used for the rotary arm to guide the incident light to the slide head on which the SIL is mounted, the structure of the recording apparatus is relatively complicated and difficult to handle.

Accordingly, the present invention has been proposed to solve the above problems and proposes a micro optical storage head device and a cartridge integrating a SIL integrated with a planar waveguide diffraction grating coupler in order to embed the head in a cartridge having a storage medium, and also to induce light. The purpose is to provide an optical storage device that can obtain a high storage density without the risk of contamination of the head and the storage medium of the optical storage device using optical fibers.

1 is a schematic diagram of an optical storage device by an optical storage head using a SIL and a waveguide diffraction grating coupler according to an embodiment of the present invention;

2 is a detail view of the sliding head of FIG. 1 in accordance with the present invention;

3 is a cross-sectional view of the micro SIL formed on the glass substrate of FIG. 2 according to the present invention;

4 is a diagram showing a near field optical storage head using a conventional SIL, and FIG. 5 is a structural diagram of a conventional disk cartridge recorded by the optical storage head of FIG.

Figure 6 is a block diagram of a disc cartridge containing an optical storage head according to an embodiment of the present invention,

7 is a structural diagram showing an apparatus for transmitting light to a disk cartridge with an optical storage head according to an embodiment of the present invention.

※ Explanation of code for main part of drawing ※

101: disc recording medium 102: the rotating arm

103: axis of rotation 104: slide head

201: optical fiber 202: flexure

203: incident light 204: planar waveguide

205: diffraction grating 206: diffraction light

207: SIL 208: Coil

209: signal light 210: glass substrate

211: recording medium 212: disk substrate

301: glass substrate 302: SIL bottom surface

303: SIL surface 304: incident light

401: laser diode 402: rotating mirror

403: parallel light 404: mirror

405: Record SIL 406: Slider

407: rotating motor 408: rotating arm

409: motor 410: coil

501: cartridge case 502: disk connection hub

503: Satter switch 504: Disc

505: disk recording surface 506: connection opening

601 cartridge case 602 disk

603: Disk Rotating Hub 604: Rotary Combiner

605: rotating arm 606: optical fiber

607: sliding head 608: recording / playback light

609: tracking direction 701: cartridge case

702: disk rotation hub 703: disk

704 recording side 705: rotary hub coupler

706: rotating arm 707: internal optical fiber

708: Slide Head 709: Fiber Optic Coupler

710: coupling rotor 711: external optical fiber

In order to achieve the above object, the optical storage device using the SIL and the waveguide diffraction grating coupler according to the present invention, in the optical storage device capable of recording / reproducing information, can rotate about the first rotating hub in the cartridge. A recording medium configured to be; An arm having one end fixed to a second rotating hub in the cartridge; A first optical waveguide provided along one surface of the arm from the second rotating hub; And a slide head connected to the first optical waveguide, wherein the slide head is installed on one surface of a flat body having an internal space and moves a second optical waveguide for moving the light received through the first optical waveguide. A plurality of diffraction gratings provided along the second optical waveguide to diffract the light transmitted along the second optical waveguide, and installed on the other surface of the inside of the planar body, and the light diffracted by the diffraction grating into one Solid Immersion Lense (SIL) focusing to focus, and a coil to generate a magnetic field around the SIL.

Hereinafter, an optical storage device using a SIL and a waveguide diffraction grating coupler according to an embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a schematic diagram of an optical storage device by an optical storage head using a SIL and a waveguide diffraction grating coupler, wherein the optical storage device includes a disc recording medium 101, a rotating arm 102, a rotating shaft 103, and a slide head 104. FIG. It is configured to include). Looking at the configuration of the optical storage device, the optical storage device records the information while flying at a constant height in close proximity to the slide head 104 at the end of the rotating arm 102 above the disk recording medium 101, like a conventional hard disk And play. The connection of information is performed while the rotating arm 102 rotates about the rotation axis 103.

2 is a detailed view of the slide head 104 of FIG. 1 in accordance with the present invention, wherein the slide head 104 is a planar waveguide 204, a diffraction grating 205, a SIL 207, a coil 208, glass It is configured to include a substrate (210).

First, the light guided by the optical fiber 201 is incident to the planar waveguide 204 on the glass substrate 210. The incident light 203 is diffracted by the diffraction grating 205 at the end of the planar waveguide 204 to form a focal point at the bottom of the SIL 207 in the glass substrate 210. In this case, the diffraction grating 205 for making the focused diffraction light 206 is designed according to the focal length at which the focal point is focused and the refractive index of the glass substrate 210. The focal point on the bottom surface of the SIL 207 transfers optical energy to the recording media 101 and 211 on the disk substrate 212 in close proximity and uses the magnetic field induced by the coil 208 around the SIL. Record it. The coil 208 generates a magnetic field to record information in a magneto-optical manner. When the information is reproduced, the signal is returned to the optical fiber via the diffraction grating 205 and the planar waveguide 204 in the opposite direction to when the signal light 209 is recorded.

3 illustrates a micro SIL 207 formed on the glass substrate 210 of FIG. 2 according to the present invention. If impurities are added to the inside of the glass substrate using an ion exchange method, the refractive index of the glass substrate can be increased, and the micro SIL is formed inside the organic substrate so that the refractive index distribution becomes hemispherical as shown in the drawing. . If the refractive index distribution changes gradually from the center of the SIL bottom face 302 to the SIL surface 303, the light path becomes curved when incident light 304 is incident on the SIL bottom face 302.

4 is a diagram illustrating a conventional near field optical storage head using a SIL, in which the optical storage head includes a coil 410 for moving the rotating arm 408, a rotating motor 407, and a SIL 405 for recording. ), A slider 406 mounted thereon, a rotating mirror 402 for guiding light, and a mirror 404 are configured. The rotary motor 407 and the coil 410 serve to move the rotary arm 408 to which the slider 406 is attached to find the track to be recorded. When the track to be recorded is found, parallel light 403 is incident on the recording medium through the rotating mirror 402 and the mirror 404.

FIG. 5 illustrates the structure of a conventional disc cartridge recorded by the optical storage head of FIG. 4, wherein the disc cartridge includes a cartridge case 501, a disc 504 coated with a recording medium, and a slider 406. As shown in FIG. And a connection opening 506 and a sector switch 503 for connecting. In the disc cartridge, when the information is recorded and reproduced, the sector switch 503 is moved to open the connection opening 506, and the slider 406 is connected to the disc recording surface 505 through the connection opening 506. At the same time, a motor is connected to the disk connection hub 502 so that the disk 504 rotates to perform recording and reproduction.

In the optical storage device performed by the combination of the slide head device of FIG. 4 and the cartridge of FIG. 5, the recording surface 505 is exposed every time the sector switcher 503 performs recording and reproduction. It is easy to be polluted by). In particular, when dust and the like are located at the focus of the SIL, recording becomes impossible, and there is a risk that the recorded information may be damaged due to scratching of the recording medium. In addition, since the small foreign matter is attached to the recording medium by opening and closing, the recording density is limited by the amount of the foreign matter.

6 is a block diagram of a disc cartridge in which the optical storage head is built according to an embodiment of the present invention. Referring to FIG. 6, the disc cartridge includes a cartridge case 601, a disc 602, a disc rotating hub 603, a rotary coupler 604, a rotary arm 605, an optical fiber 606, a slide head 607. And recording / reproducing light 608, which will be described in detail below.

Since the cartridge case 601 according to the present invention includes a disk 602 coated with a recording medium and a rotating arm 605 to which the slide head 607 is attached, the connection opening 506 and the sector switch 503 of FIG. ) Is unnecessary. The disc cartridge incorporating the optical storage head according to the present invention is possible because the head is composed of the planar waveguide 204 and the diffraction grating 205 as shown in FIG. 2 so as to be embedded in the thin cartridge case 601. The recording / reproducing light 9608 is guided by the optical fiber 606 attached to the rotating arm 605 and sent to the slide head 607. The rotary coupler 604 moves the rotary arm 605 to track in the tracking direction 609 and inputs / outputs recording / reproducing light from the outside to the optical fiber 606.

FIG. 7 is a structural diagram showing an apparatus for transmitting light to an optical storage head embedded disk cartridge according to an embodiment of the present invention, wherein the apparatus includes cartridge cases 601 and 701, a disk rotating hub 702, and a disk 703. FIG. ), Recording surface 704, rotating hub coupler 705, rotating arm 706, inner optical fiber 707, slide head 708, optical fiber combiner 709, coupling rotor 710 and external optical fiber 711 It is configured to include).

First, in order to understand that light is stored in the disc cartridge, it is necessary to understand the rotational movement of the cartridge case 701. The cartridge case 701 has two rotational motions. One of them is by the disk rotating hub 702, which serves to rotate the disk 703, and the other by the rotating hub coupler 705, which functions to rotate the rotating arm 706. The rotating hub coupler 705 is made with a groove to which the coupling rotor 710 can be fitted, and the internal optical fiber 707 of the rotating arm 706 is connected. Coupling rotor 710 has an optical fiber coupler 709 for coupling the optical fiber to the light input and output between the external optical fiber 711 and the internal optical fiber 707, the coupling rotor 710 is a rotating hub coupler 705 It is connected to the motor to rotate. Therefore, not only can the light be exchanged through the outside and the inside of the cartridge case 701 without opening and closing the cartridge case 701, but also the SIL of the recording surface 704 and the slide head 708 can not be contaminated. have.

Although the technical idea of the present invention has been described in detail according to the above preferred embodiment, it should be noted that the above-described embodiment is for the purpose of description and not of limitation. In addition, those skilled in the art will understand that various embodiments are possible within the scope of the technical idea of the present invention.

As described above, the optical storage device using the SIL and the waveguide diffraction grating coupler proposed in the present invention uses a planar waveguide diffraction grating coupler, so that a very small and ultra-light head can be obtained. Can be. In addition, since it is a near field type and head-integrated cartridge using SIL, it is protected from contamination and a high storage density can be obtained.

Claims (10)

An optical storage device capable of recording / reproducing information, A recording medium configured to rotate about the first rotating hub in the cartridge; An arm having one end fixed to a second rotating hub in the cartridge; A first optical waveguide provided along one surface of the arm from the second rotating hub; And A slide head connected to the first optical waveguide, The slide head, A second optical waveguide installed on one surface of a planar body having an internal space and moving the light transmitted through the first optical waveguide, A plurality of diffraction gratings disposed along the second optical waveguide, diffractive light diffracted along the second optical waveguide, SIL (Solid Immersion Lense) is provided on the other surface of the inside of the planar body, for converging the light diffracted by the diffraction grating into one focal point, and And a coil for generating a magnetic field around the SIL. The method of claim 1, The first rotation hub and the second rotation hub is an optical storage device, characterized in that configured to rotate by an external rotation drive source delete delete The method of claim 1, SIL of the slide head, An optical storage device, characterized in that one side is composed of a curved portion and the other side is composed of a flat portion, the curved portion is composed of a spherical or hemispherical surface or a super-hemispherical surface. The method of claim 1, The arm is, And the slide head is pivotable within an angle capable of guiding at least the slide head from the outermost track to the innermost track of the recording medium. delete The method of claim 1, And an impurity is added to the inside of the plane by an ion exchange method. The method of claim 1, The cartridge, The optical storage device, characterized in that sealed to prevent foreign matter from entering the storage medium. The method of claim 1, And the optical waveguide is formed of an optical fiber.