In-microresonator linear-absorption-based real-time photocurrent-monitoring and tuning with closed-loop control for silicon microresonators

An optical filter capable of being monitored and tuned in real-time, comprising:

• an input waveguide configured to carry optical signals in multiple wavelengths;
• an output waveguide;
• an optical microresonator coupled to the input and output waveguides to selectively transfer optical signals of at least one desired resonance wavelength from a plurality of optical signals of multiple wavelengths from the input waveguide to the output waveguide;
• a photodetector, configured to electrically read out an operation condition of the optical microresonator;
• a diode-tuner, configured to blueshift or redshift the resonance wavelength of the optical microresonator;
• a micro-heater, configured to redshift the resonance wavelength of the optical microresonator;
• a control unit, comprising a transimpedance amplifier (TIA) and a microprocessor, configured to implement a two-stage closed-loop tuning scheme utilizing the diode-tuner and the micro-heater.

An electro-optical switch capable of being monitored and tuned in real-time, comprising:

• a multimode-interference-based waveguide crossing with four ports, including an input port and an output port;
• an optical microresonator coupled to the multimode-interference-based waveguide crossing to selectively transfer light at a desired resonance wavelength received from the input port to the output port;
• a photodetector, configured to electrically read out an operation condition of the optical microresonator;
• a diode-tuner, configured to blueshift or redshift the resonance wavelength of the optical microresonator;
• a micro-heater, configured to redshift the resonance wavelength of the optical microresonator;
• a control unit, comprising a transimpedance amplifier (TIA) and a microprocessor, configured to implement a two-stage closed-loop tuning scheme utilizing the diode-tuner and the micro-heater.