# US 11,079,554 B1 · Process for polishing end face of gigabit plastic optical fiber > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 11,079,554 B1 - Document ID: US11079554B1 - Status: Granted - Kind: B1 - Application number: 16/801,981 - Filed: 2020-02-26 - Published: 2021-08-26 - Granted: 2021-08-03 - Earliest claimed: 2020-02-26 - Assignees: The Boeing Company - Applicants: The Boeing Company - Inventors: Dennis G. Koshinz; Eric Y. Chan; Kim Quan Anh Nguyen - Web page: https://patentgrep.com/patent/US11079554B1 ## CPC - G02B 6/02038: {with core or cladding having graded refractive index} - G02B 6/3863: {fabricated by using polishing techniques (grinding of the fibre ends B24B19/226)} - B24B 1/00: Processes of grinding or polishing; Use of auxiliary equipment in connection with such processes - B24B 19/226: {of the ends of optical fibres} - C09G 1/02: containing abrasives or grinding agents {(abrasives as such C09K3/14; polishing of semi-conductors H10P52/40)} - G02B 6/25: Preparing the ends of light guides for coupling, e.g. cutting - G02B 6/3857: {Crimping, i.e. involving plastic deformation} - G02B 1/045: {Light guides} - G02B 6/3854: {Ferrules characterised by materials} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS - B24B: MACHINES, DEVICES, OR PROCESSES FOR GRINDING OR POLISHING (grinding of gear teeth B23F, of screw-threads B23G1/36; by electro-erosion B23H; abrasive or related blasting B24C; tools for grinding, buffing or sharpening B24D; polishing compositions C09G1/00; abrasives C09K3/14; electrolytic etching or polishing C25F3/00; grinding arrangements for use on assembled railway tracks E01B31/17); DRESSING OR CONDITIONING OF ABRADING SURFACES; FEEDING OF GRINDING, POLISHING, OR LAPPING AGENTS - C09G: POLISHING COMPOSITIONS (French polish C09F11/00); SKI WAXES ## Abstract A process for polishing the end face of a gigabit plastic optical fiber (GbPOF) to produce a mirror smooth surface without any defect. Smooth GbPOF end faces reduce the optical coupling loss when two plastic optical fibers are connected. The polishing process can be used to produce GbPOF end faces which are free of defects such as scratches. The polishing process involves the use of successive abrasive films having decreasing surface roughness to abrade the end of a GbPOF. More specifically, each subsequently applied abrasive film has a mean particle size which is less than the mean particle size of the previously applied abrasive film. ## Claims ### Claim 1 A process for polishing an end face of a plastic optical fiber made of perfluorinated polymer material, comprising: (a) abrading a dry end face of the plastic optical fiber for a first time duration using a first abrasive film having a first mean particle size approximately equal to 3 microns; (b) after step (a), abrading the dry end face of the plastic optical fiber for a second time duration using a second abrasive film having a second mean particle size approximately equal to 1 micron; and (c) after step (b), abrading the dry end face of the plastic optical fiber for a third time duration using a third abrasive film having a third mean particle size approximately equal to 0.3 micron. ### Claim 2 (depends on 1) The process as recited in claim 1, wherein a pressure of 1.5 pounds is applied during steps (a) and (b), and a pressure of 0.5 pound is applied during step (c). ### Claim 3 (depends on 1) The process as recited in claim 1, wherein the first duration is six minutes, the second duration is four minutes, and the third duration is four minutes. ### Claim 4 (depends on 1) The process as recited in claim 1, wherein the abrasive particles of the first and second abrasive films are diamond particles. ### Claim 5 (depends on 4) The process as recited in claim 4, wherein the abrasive particles of the third abrasive film are aluminum oxide particles. ### Claim 6 (depends on 1) The process as recited in claim 1, wherein the plastic optical fiber is graded-index plastic optical fiber having a core and a cladding made of a transparent carbon-hydrogen bond-free perfluorinated polymer. ### Claim 7 (depends on 1) The process as recited in claim 1, wherein the plastic optical fiber has a data rate capability equal to at least 1 gigabit per second. ### Claim 8 (depends on 7) The process as recited in claim 7, further comprising installing the plastic optical fiber in an avionics network onboard an aircraft after step (c). ### Claim 9 A process for polishing an end face of a plastic optical fiber made of perfluorinated polymer material, comprising: (a) abrading a dry end face of the plastic optical fiber for a first time duration using a first abrasive film having a first mean particle size approximately equal to 15 microns; (b) after step (a), abrading the dry end face of the plastic optical fiber for a second time duration using a second abrasive film having a second mean particle size approximately equal to 3 microns; (c) after step (b), abrading the dry end face of the plastic optical fiber for a third time duration using a third abrasive film having a third mean particle size approximately equal to 1 micron; and (d) after step (c), abrading the dry end face of the plastic optical fiber for a fourth time duration using a fourth abrasive film having a fourth mean particle size approximately equal to 0.3 micron. ### Claim 10 (depends on 9) The process as recited in claim 9, wherein a pressure of 1.5 pounds is applied during steps (a) through (c), and a pressure of 0.5 pound is applied during step (d). ### Claim 11 (depends on 9) The process as recited in claim 9, wherein the abrasive particles of the second and third abrasive films are diamond particles, and the abrasive particles of the first and fourth abrasive films are aluminum oxide particles. ### Claim 12 (depends on 9) The process as recited in claim 9, wherein the plastic optical fiber is graded-index plastic optical fiber having a core and a cladding made of a transparent carbon-hydrogen bond-free perfluorinated polymer. ### Claim 13 (depends on 9) The process as recited in claim 9, further comprising installing the plastic optical fiber in an avionics network onboard an aircraft after step (d). ### Claim 14 A process for polishing an end face of a plastic optical fiber made of perfluorinated polymer material, comprising: (a) pressing a dry end face of the plastic optical fiber against a first abrasive film with a first pressure, wherein the abrasive particles of the first abrasive film have a first mean particle size approximately equal to 15 microns; (b) moving the first abrasive film relative to the dry end faces for a first time duration while the dry end face is being pressed against the first abrasive film with the first pressure; (c) pressing the dry end face of the plastic optical fiber against a second abrasive film with a second pressure, wherein the abrasive particles of the first abrasive film have a second mean particle size approximately equal to 3 microns; (d) moving the second abrasive film relative to the dry end face for a second time duration while the dry end face is being pressed against the second abrasive film with the second pressure; (e) pressing the dry end face of the plastic optical fiber against a third abrasive film with a third pressure, wherein the abrasive particles of the third abrasive film have a third mean particle size approximately equal to 1 micron; (f) moving the third abrasive film relative to the dry end face of the plastic optical fiber for a third time duration while the dry end face is being pressed against the third abrasive film with the third pressure; (g) pressing the dry end face of the plastic optical fiber against a fourth abrasive film with a fourth pressure, wherein the abrasive particles of the fourth abrasive film have a fourth mean particle size approximately equal to 0.3 micron; and (h) moving the fourth abrasive film relative to the dry end face of the plastic optical fiber for a fourth time duration while the dry end face is being pressed against the fourth abrasive film with the fourth pressure. ### Claim 15 (depends on 14) The process as recited in claim 14, wherein a pressure of 1.5 pounds is applied during steps (a), (c), and (e), and a pressure of 0.5 pound is applied during step (g). ### Claim 16 (depends on 14) The process as recited in claim 14, wherein the abrasive particles of the second and third abrasive films are diamond particles, and the abrasive particles of the first and fourth abrasive films are aluminum oxide particles. ### Claim 17 (depends on 14) The process as recited in claim 14, wherein the first duration is six minutes, the second duration is six minutes, the third duration is four minutes, and the fourth duration is four minutes. ### Claim 18 (depends on 14) The process as recited in claim 14, wherein the plastic optical fiber is graded-index plastic optical fiber having a core and a cladding made of a transparent carbon-hydrogen bond-free perfluorinated polymer. ### Claim 19 (depends on 14) The process as recited in claim 14, wherein the plastic optical fiber has a data rate capability equal to at least 1 gigabit per second. ### Claim 20 (depends on 14) The process as recited in claim 14, further comprising installing the plastic optical fiber in an avionics network onboard an aircraft after step (h).