US 12,292,329 B1
Receiver photodiode biasing circuit
Gianlorenzo Masini, Carlsbad, CA (US)
Assigned to Cisco Technology, Inc., San Jose, CA (US)
Filed by Cisco Technology, Inc., San Jose, CA (US)
Filed on Jan. 24, 2024, as Appl. No. 18/421,976.
Int. Cl. G01J 1/44 (2006.01); G02F 1/01 (2006.01)
CPC G01J 1/44 (2013.01) [G01J 2001/444 (2013.01); G01J 2001/446 (2013.01); G02F 1/0123 (2013.01)] 19 Claims
OG exemplary drawing
 
1. A system comprising:
an optical source arranged to produce a first optical signal;
a receiver photodiode arranged to convert a second optical signal into an electrical signal;
a first biasing photodiode arranged to generate a bias voltage for the receiver photodiode based on a first portion of the first optical signal;
a variable optical attenuator arranged to produce a third optical signal based on (i) a second portion of the first optical signal and (ii) a portion of the electrical signal; and
a compensation photodiode arranged to pass the portion of the electrical signal based on the third optical signal.