US 12,298,559 B2
Optoelectronic device
Thomas Pierre Schrans, Temple City, CA (US); Amit Singh Nagra, Altadena, CA (US); Albert Benzoni, Pasadena, CA (US); and Andrew George Rickman, Marlborough (GB)
Assigned to Rockley Photonics Limited, Altrincham (GB)
Filed by ROCKLEY PHOTONICS LIMITED, Altrincham (GB)
Filed on Nov. 16, 2022, as Appl. No. 18/056,195.
Claims priority of application No. 2116568.3 (GB), filed on Nov. 17, 2021.
Prior Publication US 2023/0280532 A1, Sep. 7, 2023
Int. Cl. G02B 6/13 (2006.01); G02B 6/12 (2006.01); G02B 6/42 (2006.01); G02F 1/015 (2006.01); G02F 1/025 (2006.01)
CPC G02B 6/13 (2013.01) [G02B 6/12004 (2013.01); G02B 6/4286 (2013.01); G02F 1/015 (2013.01); G02F 1/0155 (2021.01); G02F 1/025 (2013.01); G02B 2006/12061 (2013.01); G02B 2006/12104 (2013.01); G02B 2006/12123 (2013.01); G02B 2006/1215 (2013.01); G02B 6/4249 (2013.01)] 14 Claims
OG exemplary drawing
 
1. A power monitor comprising:
a silicon-on-insulator wafer comprising a silicon device layer and having a plurality of cavities;
a silicon input waveguide formed in the silicon device layer, the silicon input waveguide being configured to receive an optical signal;
a plurality of silicon passive waveguides formed in the silicon device layer, each of the silicon passive waveguides being between a respective adjacent pair of the cavities;
a multistage photodiode detector, comprising a plurality of photodiode elements connected in series, one of the photodiode elements of the plurality of photodiode elements being connected to the silicon input waveguide and configured to receive the optical signal therefrom, each of the plurality of photodiode elements comprising an active waveguide in a respective one of the plurality of cavities and aligned with an adjacent one of the silicon passive waveguides, the active waveguide comprising an epitaxial crystalline material different from silicon and having a ridge or rib and a slab region on either lateral side of the ridge or rib, the ridge or rib comprising an n doped sidewall and a p doped sidewall, and the slab region comprising a p+ doped region, connected to the p doped sidewall and having a higher dopant concentration than the p doped sidewall, and an n+ doped region connected to the n doped sidewall and having a higher dopant concentration than the n doped sidewall;
a first electrode and a second electrode, wherein the first electrode is connected to the p+ doped region of each of the plurality of photodiode elements, and the second electrode is connected to the n+ doped region of each of the plurality of photodiode elements; and
a first high reflectivity mirror connected to a terminating end of a first final photodiode element of the plurality of photodiode elements.