# US 10,310,185 B1 · TE polarizer based on SOI platform > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 10,310,185 B1 - Document ID: US10310185B1 - Status: Granted - Kind: B1 - Application number: 16/033,074 - Filed: 2018-07-11 - Granted: 2019-06-04 - Earliest claimed: 2018-07-11 - Assignees: Inphi Corporation - Applicants: Inphi Corporation - Inventors: Jie Lin; Masaki Kato - Web page: https://patentgrep.com/patent/US10310185B1 ## CPC - G02B 6/276: {Removing selected polarisation component of light, i.e. polarizers} - G02B 6/126: using polarisation effects {(G02B6/1226 takes precedence)} - G02B 2006/12061: {Silicon} - G02B 2006/12116: {Polariser; Birefringent} - G02B: OPTICAL ELEMENTS, SYSTEMS OR APPARATUS ## Abstract The present application discloses a Transverse Electric (TE) polarizer. The TE polarizer includes a silicon-on-insulator substrate having a silicon dioxide layer. The TE polarizer further includes a waveguide embedded in the silicon dioxide layer. Additionally, the TE polarizer includes a plate structure embedded in the silicon dioxide layer substantially in parallel to the waveguide with a gap distance. In an embodiment, the plate structure induces an extra transmission loss to a Transverse Magnetic (TM) mode in a light wave traveling through the waveguide. ## Claims ### Claim 1 A Transverse Electric (TE) polarizer comprising: a silicon-on-insulator substrate having a silicon dioxide layer; a waveguide embedded in the silicon dioxide layer; a plate structure embedded in the silicon dioxide layer substantially in parallel to the waveguide with a gap distance; wherein the plate structure induces an extra transmission loss greater than 6 dB to a Transverse Magnetic (TM) mode while keeps a low transmission loss smaller than 2 dB to a Transverse Electric (TE) mode in a light wave of a bandwidth over 30 nm traveling through the waveguide. ### Claim 2 (depends on 1) The TE polarizer of claim 1, wherein the waveguide comprises a material which has semiconducting characteristics. ### Claim 3 (depends on 2) The TE polarizer of claim 2, wherein the material which has semiconducting characteristics comprises silicon. ### Claim 4 (depends on 2) The TE polarizer of claim 2, wherein the material which has semiconducting characteristics comprises silicon nitride. ### Claim 5 (depends on 1) The TE polarizer of claim 1, wherein the plate structure comprises a material which has metallic characteristics. ### Claim 6 (depends on 5) The TE polarizer of claim 5, wherein the material which has metallic characteristics comprises titanium nitride. ### Claim 7 (depends on 1) The TE polarizer of claim 1, wherein the waveguide comprises a first length and a rectangular shaped cross section having a first width and a first thickness. ### Claim 8 (depends on 7) The TE polarizer of claim 7, wherein the plate structure comprises a second length, a second width, and a second thickness, the second length being smaller than or equal to the first length, the second width being greater than the first width, and the second thickness being smaller than the first thickness. ### Claim 9 (depends on 7) The TE polarizer of claim 7, wherein the gap distance is optimized for given dimensions of the waveguide and the plate structure such that a transmission loss of Transverse Magnetic (TM) mode in the light wave for all wavelengths in a band is greater than a first target loss and a transmission loss of Transverse Electric (TE) mode in the light wave for all wavelengths in the band is smaller than a second target loss. ### Claim 10 (depends on 9) The TE polarizer of claim 9, wherein the first target loss comprises one of 7 dB, 10 dB, and 12 dB for all wavelengths in C-band from 1525 nm to 1565 nm and the second target loss comprises one of 2 dB, 1.5 dB, 1 dB, 0.5 dB for all wavelengths in the C-band. ### Claim 11 (depends on 10) The TE polarizer of claim 10, wherein the gap distance comprises a value in a range from 0.3 μm to 2 μm. ### Claim 12 (depends on 10) The TE polarizer of claim 10, wherein the second length comprises a value of smaller than 200 μm, smaller than 250 μm, smaller than 300 μm, smaller than 500 μm, smaller than 750 μm, smaller than 1 mm, yielding a substantially linearly increasing extinction ratio. ### Claim 13 (depends on 9) The TE polarizer of claim 9, wherein the first target loss comprises one of 7 dB, 10 dB, and 12 dB for all wavelengths in O-band from 1270 nm to 1330 nm and the second target loss comprises one of 2 dB, 1.5 dB, 1 dB, 0.5 dB for all wavelengths in the O-band. ### Claim 14 A method for forming a Transverse Electric (TE) polarizer comprising: providing a silicon-on-insulator substrate having a silicon dioxide layer; forming a waveguide embedded in the silicon dioxide layer; forming a plate structure embedded in the silicon dioxide layer substantially in parallel to the waveguide with a gap distance; wherein dimensions of the waveguide and the plate structure and the gap distance between them are tuned to induce an extra transmission loss to a Transverse Magnetic (TM) mode in a light wave traveling through the waveguide greater than a first target loss of 6 dB for all wavelengths in a band over 30 nm and a transmission loss of Transverse Electric (TE) mode in the light wave is smaller than a second target loss of 2 dB for all wavelengths in the band over 30 nm. ### Claim 15 (depends on 14) The method of claim 14, wherein the forming of the waveguide comprises forming a first length and a rectangular shaped cross section having a first width and a first thickness using a material with semiconducting characteristics. ### Claim 16 (depends on 15) The method of claim 15, wherein the material with semiconducting characteristics comprises silicon. ### Claim 17 (depends on 15) The method of claim 15, wherein the material with semiconducting characteristics comprises silicon nitride. ### Claim 18 (depends on 15) The method of claim 15, wherein the forming of the plate structure comprises forming a second length, a second width, and a second thickness using a material with metallic characteristics, and optimizing the gap distance, the second length being smaller than or equal to the first length, the second width being greater than the first width, and the second thickness being smaller than the first thickness. ### Claim 19 (depends on 18) The method of claim 18, wherein the optimizing of the gap distance comprises making that the transmission loss of the Transverse Magnetic (TM) mode in the light wave for all wavelengths in C band from 1525 nm to 1565 nm is greater than the first target loss selected from 7 dB, 10 dB, and 12 dB and the transmission loss of Transverse Electric (TE) mode in the light wave for all wavelengths in C band is smaller than the second target loss selected from 2 dB, 1.5 dB, 1 dB, 0.5 dB. ### Claim 20 (depends on 19) The method of claim 19, further comprising increasing the second length from a value of smaller than 200 μm, smaller than 250 μm, smaller than 300 μm, smaller than 500 μm, smaller than 750 μm, smaller than 1 mm, yielding a substantially linearly increasing extinction ratio.