US 12,292,598 B2
Polarizing device
Lauri Lehtimäki, VTT (FI); Mikko Harjanne, VTT (FI); and Matteo Cherchi, VTT (FI)
Assigned to Teknologian tutkimuskeskus VTT Oy, Espoo (FI)
Appl. No. 18/001,974
Filed by Teknologian tutkimuskeskus VTT Oy, Espoo (FI)
PCT Filed Jun. 18, 2021, PCT No. PCT/FI2021/050468
§ 371(c)(1), (2) Date Dec. 15, 2022,
PCT Pub. No. WO2021/255347, PCT Pub. Date Dec. 23, 2021.
Claims priority of application No. 20205645 (FI), filed on Jun. 18, 2020.
Prior Publication US 2023/0333321 A1, Oct. 19, 2023
Int. Cl. G02B 6/27 (2006.01); G02B 6/28 (2006.01)
CPC G02B 6/2726 (2013.01) [G02B 6/2813 (2013.01)] 15 Claims
OG exemplary drawing
 
1. A polarizing device, comprising a multimode interferometer, wherein the multimode interferometer comprises:
a first waveguide to guide input light,
a first output portion,
a second output portion, and
wherein the polarizing device further comprises a second waveguide to guide TE-polarized light,
wherein the first waveguide is arranged to operate as a first input arm of the multimode interferometer, the first output portion is arranged to operate as a first output arm of the multimode interferometer, the second output portion is arranged to operate as a second output arm of the multimode interferometer, wherein the first waveguide and the first output portion are different portions of a same material layer, wherein an intermediate region of the material layer is arranged to operate as a multimode portion of the multimode interferometer to couple TM-polarized light from the first waveguide to the second output portion, wherein the first waveguide, the multimode portion and the first output portion together support an entire length of the second waveguide, wherein the second waveguide comprises a tapered input portion to polarization-selectively couple TE-polarized light from the first waveguide to the second waveguide, wherein the tapered input portion symmetrically overlaps the first waveguide, and a thickness of the tapered input portion has been selected to substantially prevent coupling of TM-polarized light from the first waveguide to the second waveguide, wherein a refractive index of the second waveguide is higher than a refractive index of the first waveguide.