# US 8,787,128 B2 · Near-field optical head having tapered hole for guiding light beam > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,787,128 B2 - Document ID: US8787128B2 - Status: Granted - Kind: B2 - Application number: 13/658,468 - Filed: 2012-10-23 - Published: 2013-05-09 - Granted: 2014-07-22 - Earliest claimed: 1998-11-09 - Assignees: Seiko Instruments Inc. - Applicants: Kazuko Ichihara - Inventors: Kenji Kato; Takashi Niwa; Susumu Ichihara; Norio Chiba; Manabu Oumi; Nobuyuki Kasama; Yasuyuki Mitsuoka - Web page: https://patentgrep.com/patent/US8787128B2 ## CPC - G11B 7/125: Optical beam sources therefor, e.g. laser control circuitry specially adapted for optical storage devices; Modulators, e.g. means for controlling the size or intensity of optical spots or optical traces - G11B 7/122: Flying-type heads, e.g. analogous to Winchester type in magnetic recording - G11B 7/124: the integrated head arrangements including waveguides - G11B 7/1362: Mirrors - G11B 7/1387: using the near-field effect - G11B 7/22: Apparatus or processes for the manufacture of optical heads, e.g. assembly - G01Q 80/00: Applications, other than SPM, of scanning-probe techniques (manufacture or treatment of nanostructures B82B3/00; recording or reproducing information using near-field interaction G11B9/12, G11B11/24, G11B13/08) - G02B 6/4214: {the intermediate optical element having redirecting reflective means, e.g. mirrors, prisms for deflecting the radiation from horizontal to down- or upward direction toward a device (G02B6/4246 takes precedence)} - G11B 2007/13727: {Compound lenses, i.e. two or more lenses co-operating to perform a function, e.g. compound objective lens including a solid immersion lens, positive and negative lenses either bonded together or with adjustable spacing} - G11B: INFORMATION STORAGE BASED ON RELATIVE MOVEMENT BETWEEN RECORD CARRIER AND TRANSDUCER (recording measured values in a way that does not require playback through a transducer G01D9/00; recording or playback apparatus using mechanically marked tape, e.g. punched paper tape, or using unit records, e.g. punched or magnetically marked cards G06K; transferring data from one type of record carrier to another G06K1/18; circuits for coupling output of reproducer to radio receiver H04B1/20; gramophone pick-ups or like acoustic electromechanical transducers or circuits therefor H04R) - G01Q: SCANNING-PROBE TECHNIQUES OR APPARATUS; APPLICATIONS OF SCANNING-PROBE TECHNIQUES, e.g. SCANNING PROBE MICROSCOPY [SPM] - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract A near-field optical head for recording and reading-out information on and from a recording medium by utilizing near-field light produced from a very small aperture. The very small aperture is formed at an apex of a taper formed by an optical propagation member having a tip pointed toward a recording medium. A light introducing part is connected directly to the optical propagation member for propagating light along an optical path extending in a direction generally parallel to the recording medium. The optical propagation member is formed of a uniform dielectric layer in the light introducing part and inside of the taper. A light reflection layer reflects light propagated through the light introducing part toward the very small aperture. ## Claims ### Claim 1 A near-field optical head for recording and reading-out information on and from a recording medium by utilizing near-field light produced from a very small aperture, the near-field optical head comprising: means defining a tapered hole having an apex that forms a very small aperture configured to produce near-field light; an optical propagation member for propagating light from a light incident side thereof along an optical path to the very small aperture, the optical propagation member extending continuously from the light incident side through the very small aperture and terminating in a protrusion protruding from the very small aperture; and a light reflection layer for reflecting light propagating through the optical propagation member toward the very small aperture. ### Claim 2 (depends on 1) A near-field optical head according to claim 1; wherein the protrusion has a conical or pyramidal shape. ### Claim 3 (depends on 1) A near-field optical head according to claim 1; wherein the near-field optical head is configured to be maintained at a constant position relative to the recording medium by a floating force produced by air pressure generated from high speed motion of the recording medium. ### Claim 4 (depends on 1) A near-field head according to claim 1; further comprising a slider structure opposed to the recording medium, wherein the very small aperture is formed in a surface of the slider structure. ### Claim 5 (depends on 1) A near-field optical head according to claim 1; wherein the light reflection layer has a focusing function to focus the light reflected toward the very small aperture. ### Claim 6 (depends on 1) A near-field optical head according to claim 1; wherein the light reflection layer is formed on an etched surface portion of the near-field optical head that is disposed at an angle relative to the optical path of light propagated through the optical propagation member. ### Claim 7 (depends on 1) A near-field optical head according to claim 1; wherein the means defining a tapered hole comprises a substrate having the very small aperture formed in a surface thereof opposed to the recording medium, and wherein the light reflection layer is formed on a surface of the substrate opposite the surface in which is formed the very small aperture. ### Claim 8 (depends on 1) A near-field optical head according to claim 1; wherein the means defining a tapered hole comprises a substrate having the very small aperture formed in a surface thereof opposed to the recording medium; and wherein the light reflection layer is formed on the surface of the substrate in which is formed the very small aperture. ### Claim 9 (depends on 1) A near-field optical head according to claim 1; wherein the optical propagation member has, along the optical path, two or more stages of slant surfaces having different angles of slant. ### Claim 10 (depends on 1) A near-field optical head according to claim 1; wherein the tapered hole has a conical or a pyramidal shape. ### Claim 11 (depends on 10) A near-field optical head according to claim 10; wherein the protrusion has a conical or a pyramidal shape. ### Claim 12 (depends on 1) A near-field optical head according to claim 1; wherein both the tapered hole and the protrusion have a conical or a pyramidal shape. ### Claim 13 (depends on 1) A near-field optical head according to claim 1; wherein the optical propagation member is made of dielectric material. ### Claim 14 (depends on 1) A near-field optical head according to claim 1; wherein the means defining a tapered hole comprises a substrate having the very small aperture formed therein, the light reflection layer is formed on the substrate, and the optical propagation member is formed on the light reflection layer. ### Claim 15 (depends on 14) A near-field optical head according to claim 14; wherein the optical propagation member comprises a dielectric layer formed on the light reflection layer. ### Claim 16 (depends on 1) A near-field optical head according to claim 1; wherein the protrusion protrudes from the very small aperture less than 200 nm.