Abstract: A wavelength calibration method for a microring filter includes selecting N wavelengths from M wavelengths, and performing operations on the microring filter for each of the N wavelengths, thereby obtaining N sets of calibrated voltages, and obtaining, based on N sets of calibrated voltages, M?N sets of calibrated voltages corresponding to M?N wavelengths of the M wavelengths. The operating include adjusting thermal tuning power of the plurality of microrings in response to one set of voltages, and obtaining a plurality of sets of voltages that enable monitored optical power to have an extreme value, and using the plurality of sets of voltages as a reference, adjusting the thermal tuning power of the plurality of microrings in response to another set of voltages, and determining one of the N sets of calibrated voltages from the plurality of sets of voltages.

Abstract: An ADD/DROP filter and an optical add/drop multiplexer are disclosed. An ADD/DROP filter includes an input port, an output port, an add port connecting to a modulator, and a drop port. The modulator is configured to load a pilot signal to a first optical signal to obtain a second optical signal, and transmit the second optical signal to the add port. A third optical signal is input to the input port. A wavelength difference between the second optical signal and the third optical signal is an integral multiple of a free spectral range. A power detector is connected to the output port and/or the drop port. The power detector is configured to obtain an output optical signal from the output port or the drop port and detect an optical power of the output optical signal.

Abstract: A wavelength calibration method, apparatus, and system is disclosed. The method includes: selecting sonic wavelengths from a plurality of wavelengths, and performing the following operations on a microring filter for each of the some wavelengths, to obtain sets of calibrated voltages of the some wavelengths: (1) adjusting thermal tuning power of multiple microrings by using one set of voltages, and obtaining multiple sets of voltages that enable monitored optical power to have an extreme value, and (2) using the multiple of sets of voltages as a reference, adjusting the thermal tuning power of the multiple microrings by using another set of voltages, and determining one of the sets of calibrated voltages, which enables the monitored optical power to converge, from the multiple sets of voltages; and then, obtaining, through calculation based on the sets of calibrated voltages of the some wavelengths, sets of calibrated voltages of other wavelengths.

Abstract: An ADD/DROP filter and an optical add/drop multiplexer are disclosed. An ADD/DROP filter includes an input port, an output port, an add port connecting to a modulator, and a drop port. The modulator is configured to load a pilot signal to a first optical signal to obtain a second optical signal, and transmit the second optical signal to the add port. A third optical signal is input to the input port. A wavelength difference between the second optical signal and the third optical signal is an integral multiple of a free spectral range. A power detector is connected to the output port and/or the drop port. The power detector is configured to obtain an output optical signal from the output port or the drop port and detect an optical power of the output optical signal.