Wavelength control and monitor for dense wavelength division multiplexing (DWDM) silicon photonic receiver

A method comprising:

• applying an output code from an analog-to-digital converter (ADC) as a wavelength monitor;
• applying an input code to a digital-to-analog converter (DAC) as a wavelength controller to determine wavelength shifts of a MDF;
• determining a relative location of the MDF resonance wavelength (R) to the incident WDM wavelength (λ);
• adjusting the resonant wavelength (R) of the MDF until the resonant wavelength (R) of the MDF matches the incident WDM wavelength (λ);
• setting a DAC input code to a first value (D0);
• storing a first ADC output code (A1) to correspond the first ADC output code (A1) to the first value of the DAC input code (D0);
• setting the DAC input code to a second value for the DAC input code (D1), wherein the second value for the DAC input code (D1) is larger than the first value for the DAC input code (D0) such that the DAC generates a current value corresponding to the second value for the DAC input code (D1) for driving a heating resistor at the MDF that is larger than a current value corresponding to the first value for the DAC input code (D0) by a static step size;
• storing a second ADC output code (A2) to correspond the second ADC output code (A2) to the second value for the DAC input code (D1);
• setting the DAC input code to a third value for the DAC input code (D2), wherein the third value for the DAC input code (D2) is larger than the second value for the DAC input code (D1) such that the DAC generates a current value corresponding to the third value for the DAC input code (D2) for driving the heating resistor at the MDF that is larger than the current value corresponding to the second value for the DAC input code (D1) by a static step size;
• and
• storing a third ADC output code (A3) to correspond the third ADC output code (A3) to the third value for the DAC input code (D2).

A multi-channel dense-wavelength-division-multiplexing (DWDM) silicon photonic receiver, comprising:

• an optical receiver, wherein the optical receiver comprises a microring drop filter (MDF) having an incident optical wavelength corresponding to a wavelength from multiple wavelengths for multiple DWDM channels;
• a wavelength monitor to detect signals from the optical receiver indicating a resonant wavelength of the MDF;
• a wavelength division multiplexing (WDM) digital logic controller to determine an amount of deviation between the resonant wavelength of the MDF and the incident optical wavelength of the MDF based on the detected signals;
• and
• a wavelength controller to tune the resonant wavelength of the MDF via thermal wavelength shifting based on the compensation factor;
• wherein the wavelength monitor comprises a peak detector and a direct current (dc) detector by reusing circuitry of an automatic gain control (AGC) portion of the optical receiver.