# US 9,437,229 B2 · Isolator element for heat-assisted magnetic recording > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 9,437,229 B2 - Document ID: US9437229B2 - Status: Granted - Kind: B2 - Application number: 14/680,252 - Filed: 2015-04-07 - Published: 2015-10-15 - Granted: 2016-09-06 - Earliest claimed: 2014-04-09 - Assignees: Seagate Technology LLC - Applicants: Seagate Technology LLC - Inventors: Karim Tatah - Web page: https://patentgrep.com/patent/US9437229B2 ## CPC - G11B 5/4866: {the arm comprising an optical waveguide, e.g. for thermally-assisted recording} - G02B 6/4208: {using non-reciprocal elements or birefringent plates, i.e. quasi-isolators (optical isolators per se G02F1/093, G02F1/0955)} - G11B 5/105: Mounting of head within housing {or assembling of head and housing (G11B5/3103 takes precedence)} - G11B 5/6088: {Optical waveguide in or on flying head} - G11B 7/1384: Fibre optics - H01S 5/0064: {Anti-reflection components, e.g. optical isolators} - H01S 5/02251: using optical fibres - H01S 5/02325: Mechanically integrated components on mount members or optical micro-benches - H01S 5/34: comprising quantum well or superlattice structures, e.g. single quantum well [SQW] lasers, multiple quantum well [MQW] lasers or graded index separate confinement heterostructure [GRINSCH] lasers (H01S5/36 takes precedence) - G11B 5/314: {where the layers are extra layers normally not provided in the transducing structure, e.g. optical layers (G11B5/3196 takes precedence)} - G11B 2005/001: {Controlling recording characteristics of record carriers or transducing characteristics of transducers by means not being part of their structure} - G11B 2005/0021: {Thermally assisted recording using an auxiliary energy source for heating the recording layer locally to assist the magnetization reversal} - 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 - H01S: DEVICES USING THE PROCESS OF LIGHT AMPLIFICATION BY STIMULATED EMISSION OF RADIATION [LASER] TO AMPLIFY OR GENERATE LIGHT; DEVICES USING STIMULATED EMISSION OF ELECTROMAGNETIC RADIATION IN WAVE RANGES OTHER THAN OPTICAL ## Abstract An apparatus with a slider body, a laser diode, and an isolator element. The slider body has an optical pathway extending therealong. The laser diode is configured to emit light along the optical pathway. The isolator element is disposed in the optical pathway to reduce optical feedback along the optical pathway back to the laser diode. In some embodiments, the isolator element is disposed in the optical pathway between the laser diode and the slider body. ## Claims ### Claim 1 An apparatus, comprising: a slider body having an optical pathway extending therealong; a laser diode configured to emit light along the optical pathway; and an isolator element disposed in the optical pathway to reduce optical feedback along the optical pathway back to the laser diode, the isolator element comprising a magneto-optical photonic crystal including a plurality of magneto-optical film layers and a plurality of photonic band gap film layers, wherein at least some of the plurality of magneto-optical film layers are separated from one another by one of the plurality of band gap film layers. ### Claim 2 (depends on 1) The apparatus of claim 1, wherein the magneto-optical photonic crystal has characteristics of a seven reflector single cavity crystal according to the equation [M/N]x[M]y[N/M]x, where M=Bi2.97Er0.03Fe4Ga0.5Al0.5O12, N=Sm3Ga5O12, x=any integer, and y=any integer. ### Claim 3 (depends on 1) The apparatus of claim 1, wherein the plurality of magneto-optical film layers are comprised of one or more of a bismuth iron garnet and a yttrium iron-indium garnet, and wherein the plurality of photonic band gap film layers are comprised of one or more of a samarium gallium garnet and a gadolinium gallium garnet. ### Claim 4 (depends on 1) The apparatus of claim 1, wherein the plurality of magneto-optical film layers comprise Bi2.97Er0.03Fe4Ga0.5Al0.5O12 and the plurality of photonic band gap film layers comprise Sm3Ga5O12. ### Claim 5 (depends on 1) The apparatus of claim 1, wherein the isolator element has a thickness between about 5 and 25 microns. ### Claim 6 (depends on 1) The apparatus of claim 1, wherein the isolator element is disposed between an output facet of the laser diode and an input coupler of the optical pathway within the slider body. ### Claim 7 (depends on 1) The apparatus of claim 1, wherein the isolator element is fabricated as part of or is disposed upon a submount for the laser diode. ### Claim 8 (depends on 1) The apparatus of claim 1, wherein the isolator element is fabricated as part of the slider body at an input coupler of the optical pathway to the slider body. ### Claim 9 (depends on 1) The apparatus of claim 1, wherein the isolator element is fabricated as part of an output facet of the laser diode. ### Claim 10 (depends on 1) The apparatus of claim 1, wherein the isolator element is fabricated as a chip that is assembled to one or more of the slider body, the laser diode, or a submount. ### Claim 11 (depends on 1) The apparatus of claim 1, wherein the isolator element includes one or more of a horizontal polarizer, a 45° linear polarizer, a half-wave plate, and a 45° polarization rotator. ### Claim 12 (depends on 1) The apparatus of claim 1, wherein the isolator element includes a micro-lens. ### Claim 13 An apparatus comprising: a system configured to facilitate heat assisted magnetic recording, comprising: a slider body; a laser diode mounted to the slider body; and an isolator element disposed in an optical pathway between the laser diode and the slider body to reduce optical feedback along the optical pathway back to the laser diode, the isolator element comprising a magneto-optical photonic crystal having characteristics of a seven reflector single cavity crystal according to the equation [M/N]x[M]y[N/M]x, where M=Bi2.97Er0.03Fe4Ga0.5Al0.5O12, N=Sm3Ga5O12, x=any integer, and y=any integer. ### Claim 14 A method, comprising: providing an apparatus configured to facilitate heat assisted magnetic recording having a laser diode; and disposing an isolation element in an optical pathway of the apparatus to reduce optical feedback to the laser diode, the isolation element comprising a magneto-optical photonic crystal including a plurality of magneto-optical film layers and a plurality of photonic band gap film layers, wherein at least some of the plurality of magneto-optical film layers are separated from one another by one of the plurality of band gap film layers. ### Claim 15 (depends on 14) The method of claim 14, wherein the step of disposing the isolation element along the optical pathway includes fabricating the isolation element as part of one or more of a slider body, the laser diode, a submount, and a chip. ### Claim 16 (depends on 15) The method of claim 15, wherein the step of fabricating includes one or more of sputtering, atomic layer deposition, evaporation, and ion beam deposition. ### Claim 17 (depends on 14) The method of claim 14, wherein the step of disposing the isolation element along the optical pathway includes mounting the isolation element to one or more of the slider body and the laser diode. ### Claim 18 (depends on 14) The method of claim 14, the step of fabricating includes forming a refractive or defractive micro-lens on one or more layers of the isolation element.