US 11,988,870 B2
Bilayer silicon nitride polarization splitter and rotator
Jean-Luc Joseph Tambasco, Macungie, PA (US)
Assigned to CISCO TECHNOLOGY, INC., San Jose, CA (US)
Filed by Cisco Technology, Inc., San Jose, CA (US)
Filed on Feb. 18, 2022, as Appl. No. 17/675,057.
Prior Publication US 2023/0266531 A1, Aug. 24, 2023
Int. Cl. G02B 6/12 (2006.01); G02B 6/122 (2006.01); G02B 6/125 (2006.01)
CPC G02B 6/1228 (2013.01) [G02B 6/125 (2013.01); G02B 2006/12061 (2013.01); G02B 2006/1215 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A device comprising:
a substrate;
a first optical waveguide disposed in the substrate at a first layer, the first optical waveguide having a substantially rectangular shape and longitudinally arranged between a first end of the first optical waveguide and a second end of the first optical waveguide; and
a second optical waveguide, disposed in the substrate at a second layer, vertically, in cross-section, above the first layer, and arranged to have a partial and fixed amount of overlap with, and over a predetermined length of, the first optical waveguide,
wherein a first end of the second optical waveguide curves towards a first side of the first optical waveguide, and a second end of the second optical waveguide curves away from the first side of the first optical waveguide, and
wherein the second optical waveguide comprises, at a first end of the second optical waveguide, a bent end that narrows to a tip that is translated away from the first optical waveguide.