Method of tuning optical components integrated in a monolithic photonic integrated circuit (PIC)

An optical tuning method comprising the steps:

• producing a plurality of optical signals with a plurality of first optical components provided on a semiconductor substrate, each of the plurality of optical signals having a corresponding one of a plurality of emission wavelengths;
• coupling each of the plurality of optical signals to a corresponding one of a plurality of second optical components provided on the semiconductor substrate, each of the plurality of second optical components superimposing a respective one of a plurality of tones onto a corresponding one of the plurality of optical signals;
• combining the plurality of optical signals in a third optical component provided on the semiconductor substrate, the plurality of optical signals being combined into an output signal provided at an output of the third optical component;
• recovering the plurality of tones from a portion of the output signal;
• identifying a desired emission wavelength, the desired emission wavelength being associated with one of the plurality of tones;
• tuning one of the plurality of emission wavelengths by reducing a spectral difference between said one of the plurality of emission wavelengths and the desired emission wavelength;
• and
• coupling each of the plurality of optical signals to a corresponding one of a plurality of fourth optical components on the semiconductor substrate, each of the plurality of fourth optical components attenuating a corresponding one of the plurality of optical signals,
• wherein each of the plurality of optical signals has a corresponding one of a plurality of optical power values at an output of a corresponding one of the plurality of fourth optical components, one of the plurality of optical power values being different than remaining ones of the plurality of optical power values.