US 12,242,109 B2
Dual layer optical coupling configuration between photonic integrated circuit and external single mode optical fiber
Ravinder Kachru, San Jose, CA (US); Anujit Shastri, Saratoga, CA (US); Rao Yelamarty, Allentown, PA (US); Sriram Tyagarajan, Macungie, PA (US); David Snyder, Coopersburg, PA (US); and Kalpendu Shastri, Orefield, PA (US)
Assigned to Aayuna Inc., Allentown, PA (US)
Appl. No. 18/271,878
Filed by Aayuna Inc., Allentown, PA (US)
PCT Filed Jan. 13, 2022, PCT No. PCT/US2022/012301
§ 371(c)(1), (2) Date Jul. 12, 2023,
PCT Pub. No. WO2022/155326, PCT Pub. Date Jul. 21, 2022.
Claims priority of provisional application 63/138,642, filed on Jan. 18, 2021.
Prior Publication US 2024/0069286 A1, Feb. 29, 2024
Int. Cl. G02B 6/125 (2006.01); G02B 6/293 (2006.01); G02B 6/30 (2006.01); G02B 6/12 (2006.01); G02B 6/28 (2006.01)
CPC G02B 6/125 (2013.01) [G02B 6/29331 (2013.01); G02B 6/30 (2013.01); G02B 2006/1215 (2013.01); G02B 6/2821 (2013.01)] 16 Claims
OG exemplary drawing
 
1. A dual-layer coupling arrangement for providing optical signal coupling between a signal-supporting optical waveguide formed within a photonic integrated circuit (PIC) and an external optical signal path, the arrangement comprising
a first coupling waveguide formed within a first layer of the PIC at a location above the signal-supporting optical waveguide and comprising a material with a refractive index value that promotes evanescent coupling between the signal-supporting optical waveguide and the first coupling waveguide, the first coupling waveguiding formed as a splitter waveguide arrangement terminating near a side edge of the PIC as a first pair of waveguide arms separated by a width W, the splitter waveguide arrangement configured to direct half of the propagating beam energy into each waveguide arm; and
a second coupling waveguide formed within a second layer of the PIC at a location above the first coupling waveguide, the second coupling waveguide vertically spaced above the first coupling waveguide by a separation S and comprising a material with a refractive index value that promotes evanescent coupling of a propagating optical signal between the first coupling waveguide and the second coupling waveguide, the second coupling waveguide formed as a splitter waveguide arrangement terminating near the side edge of the PIC as a second pair of waveguide arms separated by a width W, the splitter waveguide arrangement configured to direct half of the propagating beam energy into each waveguide arm of the second pair of waveguide arms, wherein the values of W and S are selected such that a set of beams associated with the edge terminations from the first and second coupling waveguides coincide with a circular mode profile of an external optical transmission path positioned along the side edge of the PIC for coupling to the included signal-supporting optical waveguide.