# US 6,724,718 B1 · Near field optical head and method for manufacturing thereof > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 6,724,718 B1 - Document ID: US6724718B1 - Status: Granted - Kind: B1 - Application number: 09/806,649 - Filed: 2001-05-07 - Granted: 2004-04-20 - Earliest claimed: 1999-08-25 - Assignees: Seiko Instruments Inc. - Inventors: Yoko Shinohara; Takashi Niwa; Susumu Ichihara; Yasuyuki Mitsuoka; Manabu Oumi; Nobuyuki Kasama; Kenji Kato - Web page: https://patentgrep.com/patent/US6724718B1 ## CPC - G11B 7/22: Apparatus or processes for the manufacture of optical heads, e.g. assembly - G02B 6/262: {Optical details of coupling light into, or out of, or between fibre ends, e.g. special fibre end shapes or associated optical elements} - G11B 5/59677: {with optical servo tracking} - G11B 7/122: Flying-type heads, e.g. analogous to Winchester type in magnetic recording - G11B 21/21: with provision for maintaining desired spacing of head from record carrier, e.g. fluid-dynamic spacing, slider - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - G02B 6/3636: {the mechanical coupling means being grooves (G02B6/3652 takes precedence)} - G02B 6/3652: {the additional structures being prepositioning mounting areas, allowing only movement in one dimension, e.g. grooves, trenches or vias in the microbench surface, i.e. self aligning supporting carriers} - 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)} - G02B 6/4296: {coupling with sources of high radiant energy, e.g. high power lasers, high temperature light sources} - 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) - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract A near-field optical head has a slider having a minute aperture for emitting near-field light. The minute aperture has a diameter equal to or less than a wavelength of visible light. The slider is supported by a suspension arm for exerting a load, receiving a floating force due to relative movement with a recording medium, and forming a gap between the slider and the recording medium through a balance between the load and the floating force. A light propagating medium has an output end for emitting light. An optical path length shortening structure shortens an optical path length between the output end of the light propagating medium and the minute aperture of the slider. A mirror is disposed over the slider for guiding light emitted from the light propagating medium to the minute aperture of the slider. ## Claims ### Claim 1 A near-field optical head comprising: a slider supported by a suspension arm for exerting a load, receiving a floating force due to relative movement with a recording medium, and forming a gap between the slider and the recording medium through a balance between the load and the floating force; a means defining a minute aperture for emitting near-field light and formed on the recording medium side of the slider, the minute aperture having a diameter equal to or less than a wavelength of visible light; a light propagating medium disposed on a surface of the slider opposite to the recording medium side generally in parallel with the suspension arm; a mirror disposed generally above the minute aperture for guiding light emitted from the light propagating medium to the minute aperture; and an optical path shortening structure for shortening an optical path length between an output end of the light propagating medium and the minute aperture. ### Claim 2 (depends on 1) A near-field optical head according to claim 1; wherein the optical path shortening structure comprises a groove formed in the vicinity of the minute aperture; and wherein the light propagating medium is disposed in the groove. ### Claim 3 (depends on 2) A near-field optical head according to claim 2; wherein the mirror is disposed on and is integral with a substrate disposed above the slider. ### Claim 4 (depends on 2) A near-field optical head according to claim 2; wherein the mirror is formed on the light propagating medium. ### Claim 5 (depends on 4) A near-field optical head according to claim 4; wherein the mirror is generally concave-shaped for condensing the light emitted from the light propagating medium. ### Claim 6 (depends on 5) A near-field optical head according to claim 5; wherein the light propagating body generally concave-shaped mirror has a lens function for condensing light on a tip of the light propagating medium. ### Claim 7 (depends on 1) A near-field optical head according to claim 1; wherein the diameter of the minute aperture is 300 nm or less. ### Claim 8 (depends on 1) A near-field optical head according to claim 1; wherein the diameter of the minute aperture is 100 nm. ### Claim 9 (depends on 1) A near-field optical head according to claim 1; wherein the diameter of the minute aperture is in the range of 50-300 nm. ### Claim 10 A near-field optical head comprising: a slider supported by a suspension arm for exerting a load, receiving a floating force due to relative movement with a recording medium and forming a gap between the slider and the recording medium through a balance between the load and the floating force; a microstructure formed on the recording medium side of the slider; a light propagating medium disposed on a surface of the slider opposite to the recording medium side generally in parallel with the suspension arm; a mirror formed on the light propagating medium and disposed generally above the microstructure for guiding light emitted from the light propagating medium to the microstructure, the mirror being generally concave-shaped and having a lens function for condensing light emitted from the light propagating medium on a tip of the light propagating medium; and a mirror alignment mechanism formed on the slider and/or the substrate for setting a position of the mirror and the microstructure. ### Claim 11 (depends on 10) A near-field optical head according to claim 10; further comprising an optical component for directing light into the light propagating medium and being supported in a groove or by a protrusion formed in the substrate. ### Claim 12 (depends on 11) A near-field optical head according to claim 11; wherein the light propagating medium is formed on the slider. ### Claim 13 (depends on 11) A near-field optical head according to claim 11; wherein the light propagating medium is formed on a side of the slider on which the mirror is disposed. ### Claim 14 (depends on 11) A near-field optical head according to claim 11; wherein the light propagating medium has an input end connected to the substrate and the output end connected to the slider. ### Claim 15 (depends on 14) A near-field optical head according to claim 14; wherein the light propagating medium comprises an optical fiber having an optical axis and a tip disposed generally parallel to the optical axis. ### Claim 16 (depends on 14) A near-field optical head according to claim 14; wherein the light propagating medium comprises a light waveguide. ### Claim 17 A method for manufacturing a near-field optical head, comprising the steps of: forming a mirror by forming a protrusion on a substrate and forming a reflection film on the protrusion; forming a slider by forming a hole in a substrate, forming at a terminal end of the hole a minute aperture for emitting near-field light and having a diameter equal to or less than a wavelength of visible light, forming an optical path shortening structure in the substrate in communication with the minute aperture, and forming a reflection coating on a surface of the hole; and disposing the mirror over the slider. ### Claim 18 (depends on 17) A method for manufacturing a near-field optical head according to claim 17; further comprising the step of connecting an optical fiber on the slider or the mirror before the disposing step. ### Claim 19 (depends on 17) A method for manufacturing a near-field optical head according to claim 17; further comprising the step of forming a thin film waveguide on one of the slider or the mirror before the disposing step. ### Claim 20 (depends on 19) A method for manufacturing a near-field optical head according to claim 19; wherein the step of forming a mirror further comprises the step of forming a groove or a protrusion in the substrate for supporting optical components. ### Claim 21 (depends on 18) A method for manufacturing a near-field optical head according to claim 18; further comprising the step of grinding a tip of the optical fiber to sharpen the tip and so that the tip is parallel with an optical axis of the optical fiber. ### Claim 22 (depends on 18) A method for manufacturing a near-field optical head according to claim 18; further comprising the step of shaping a tip of the optical fiber to form a surface extending along a plane inclined to an optical axis of the optical fiber probe; and forming a reflection coating on the surface of the tip of the optical fiber probe. ### Claim 23 (depends on 22) A method for manufacturing a near-field optical head according to claim 22; further comprising the step of machining the tip of the optical fiber to form a lens for condensing light emitted from the optical fiber onto the minute aperture. ### Claim 24 (depends on 17) A method according to claim 17; wherein the diameter of the minute aperture is 300 nm or less. ### Claim 25 (depends on 17) A method according to claim 17; wherein the diameter of the minute aperture is 100 nm. ### Claim 26 (depends on 15) A method according to claim 15; wherein the diameter of the minute aperture is in the range of 50-300 nm. ### Claim 27 A near-field optical head comprising: a light propagating medium for emitting light; a mirror for reflecting the light emitted from the light propagating medium; means defining a minute aperture for emitting near-field light and arranged in the direction of the light reflected by the mirror for receiving the reflected light, the minute aperture having a diameter equal to or less than a wavelength of visible light; and a slider having a suspension arm for supporting the light propagating medium, the mirror, and the minute aperture, exerting a load, receiving a floating force due to relative movement with a recording medium, and forming a gap between the minute aperture and the recording medium through a balance between the load and the floating force. ### Claim 28 (depends on 27) A near-field optical head according to claim 27; wherein the light propagating medium has a core portion for propagating light and extending toward the recording medium. ### Claim 29 (depends on 27) A near-field optical head according to claim 27; wherein the light propagating medium comprises at least a part of the suspension arm. ### Claim 30 (depends on 29) A near-field optical head according to claim 29; wherein the mirror is disposed on and is integral with a substrate disposed above the slider. ### Claim 31 (depends on 27) A near-field optical head according to claim 27; wherein the diameter of the minute aperture is 300 nm or less. ### Claim 32 (depends on 27) A near-field optical head according to claim 27; wherein the diameter of the minute aperture is 100 nm. ### Claim 33 (depends on 27) A near-field optical head according to claim 27; wherein the diameter of the minute aperture is in the range of 50-300 nm. ### Claim 34 A near-field optical head comprising: a slider supported by a suspension arm for exerting a load, receiving a floating force due to relative movement with a recording medium, and forming a gap between the slider and the recording medium through a balance between the load and the floating force, the slider having a minute aperture for emitting near-field light, the minute aperture having a diameter equal to or less than a wavelength of visible light; a light propagating medium having an output end for emitting light; optical path length shortening means for shortening an optical path length between the output end of the light propagating medium and the minute aperture; and a mirror disposed over the slider for guiding light emitted from the light propagating medium to the minute aperture of the slider. ### Claim 35 (depends on 34) A near-field optical head according to claim 34; wherein the slider has a groove; and wherein the mirror has a protrusion disposed in the groove of the slider to define the optical path length shortening means. ### Claim 36 (depends on 34) A near-field optical head according to claim 34; wherein the groove of the slider is generally V-shaped and the protrusion of the mirror is generally U-shaped. ### Claim 37 (depends on 34) A near-field optical head according to claim 34; wherein the light propagating medium comprises an optical fiber having an optical axis and a tip portion extending generally parallel to the optical axis. ### Claim 38 (depends on 37) A near-field optical head according to claim 37; wherein the optical fiber is disposed generally parallel to the suspension arm. ### Claim 39 (depends on 34) A near-field optical head according to claim 34; wherein the light propagating medium is disposed generally parallel to the suspension arm. ### Claim 40 (depends on 34) A near-field optical head according to claim 34; wherein the diameter of the minute aperture is 300 nm or less. ### Claim 41 (depends on 34) A near-field optical head according to claim 34; wherein the diameter of the minute aperture is 100 nm. ### Claim 42 (depends on 34) A near-field optical head according to claim 34; wherein the diameter of the minute aperture is in the range of 50-300 nm.