Method and system for balancing optical receiver

A transimpedance amplifier circuit, comprising:

• a first input terminal configured to obtain a first photocurrent from a first photodetector in a photodetector circuit;
• a second input terminal configured to obtain a second photocurrent from a second photodetector in the photodetector circuit;
• an amplifier configured to output, using the first photocurrent and the second photocurrent, a first output signal and a second output signal;
• a first transimpedance gain controller configured to reduce a difference in photodetector responsivity at the amplifier between the first photodetector and the second photodetector;
• and
• a first frequency response controller configured to match a first frequency response of a first photocurrent path from the first photodetector to a second frequency response of a second photocurrent path from the second photodetector, wherein the first frequency response and the second frequency response describe an output of the amplifier for a range of Alternating Current (AC) frequencies for the first photocurrent path and the second photocurrent path, respectively.

A method, comprising:

• transmitting an optical noise signal to a first photodetector and a second photodetector within an optical receiver circuit comprising a transimpedance amplifier circuit;
• measuring, in response to transmitting the optical noise signal, a power output from the optical receiver circuit;
• determining, using the power output, a difference in photodetector responsivity between the first photodetector and the second photodetector;
• adjusting, using a transimpedance gain controller, an amplifier gain within the optical receiver circuit to decrease the difference in photodetector responsivity between the first photodetector and the second photodetector;
• determining a difference between a first frequency response of a first photocurrent path and a second frequency response of a second photocurrent path within the optical receiver circuit, wherein the first frequency response and the second frequency response describe an output of respective amplifiers for a range of Alternating Current (AC) frequencies for the first photocurrent path and the second photocurrent path, respectively;
• and
• adjusting, using a frequency response controller, the first frequency response to decrease the difference between the first frequency response and the second frequency response.