Photonic apparatus with bias control to provide substantially constant responsivity of a photodetector

A method, comprising:

• receiving, by a first photodetector of an apparatus, an optical input, wherein the first photodetector is to provide a corresponding electrical output in response to receiving the optical input, and wherein the first photodetector is coupled with a second photodetector of the apparatus;
• generating, by a circuitry coupled with the first and second photodetectors of the apparatus, a bias voltage, based at least in part on a dark current generated by the second photodetector in an absence of the optical input;
• providing, by the circuitry, the generated bias voltage to the first photodetector, wherein the first photodetector is to provide a substantially constant ratio of the electrical output to optical input in response to the providing of the generated bias voltage;
• adjusting, by the circuitry, the dark current generated by the second photodetector in the absence of the optical input when the optical input exceeds a power level threshold;
• correspondingly adjusting, by the circuitry, the bias voltage based at least in part on the adjusted dark current;
• and
• generating, by the circuitry, a dark current reference, based at least in part on a table including dark current values and corresponding responsivity values, wherein the responsivity values comprise a ratio of the electrical output to optical input, wherein the adjusting of the dark current includes providing, by the circuitry, the dark current based at least in part on the generated dark current reference.

A computing device, comprising:

• a processor, to generate data;
• and
• a transceiver coupled with the processor, to transmit the generated data, wherein the transceiver includes:
• a first photodetector, to receive an optical input and provide a corresponding electrical output;
• a second photodetector coupled with the first photodetector, wherein the second photodetector is free from receipt of the optical input;
• and circuitry coupled with the first and second photodetectors, to:
• generate a bias voltage, based at least in part on a dark current generated by the second photodetector in an absence of the optical input;
• and provide the generated bias voltage to the first photodetector, wherein the first photodetector is to provide a substantially constant ratio of the electrical output to optical input in response to the provision of the generated bias voltage, wherein the circuitry includes logic to generate the dark current based at least in part on a look-up table that provides dark current values that correspond to responsivity values of the first photodetector, wherein the responsivity values comprise a substantially constant value.