Optical Source Monitoring in Optical Communication System

A method for mapping resonance wavelengths of wavelength selective modulators across an optical transmit macro of an electro-optical chip, comprising:

• conveying a plurality of wavelengths of continuous wave light through a transmit bus optical waveguide that extends through a plurality of transmit slices of an optical transmit macro of an electro-optical chip, wherein each of the plurality of transmit slices includes a wavelength selective modulator optically coupled to the transmit bus optical waveguide, the wavelength selective modulator configured to modulate a selected one of the plurality of wavelengths of continuous wave light that is being conveyed through the transmit bus optical waveguide;
• operating the wavelength selective modulator in each of the plurality of transmit slices to modulate said selected one of the plurality of wavelengths of continuous wave light that is being conveyed through the transmit bus optical waveguide;
• operating a scanning detector to divert a portion of light having a particular wavelength from the transmit bus optical waveguide to a mapping bus optical waveguide, wherein the portion of light diverted by the scanning detector is a mapping light, and wherein the particular wavelength of the mapping light is a mapping wavelength, wherein the mapping bus optical waveguide extends from the scanning detector through the plurality of transmit slices;
• operating a phase shifter to impart a phase modulation pattern onto the mapping light conveyed through the mapping bus optical waveguide at a location upstream from the plurality of transmit slices relative to a light propagation direction through the mapping bus optical waveguide;
• and
• combining a portion of the mapping light from the mapping bus optical waveguide with a drop portion of light currently optically coupled into the wavelength selective modulator in each of the plurality of transmit slices to determine whether or not the phase modulation pattern of the mapping light is imparted onto the drop portion of light, wherein imparting of the phase modulation pattern of the mapping light onto the drop portion of light is indicative of a match between the mapping wavelength of the mapping light and a resonance wavelength of the wavelength selective modulator from which the drop portion of light is obtained.

An optical transmit macro of an electro-optical chip, comprising:

• a transmit bus optical waveguide optically connected to an optical supply input;
• a plurality of transmit slices, the transmit bus optical waveguide extending through the plurality of transmit slices, each of the plurality of transmit slices including a wavelength selective modulator optically coupled to the transmit bus optical waveguide, the wavelength selective modulator configured to modulate a selected wavelength of light that is being conveyed through the transmit bus optical waveguide, each of the plurality of transmit slices including a photodetector optically connected to receive a drop portion of light currently coupled into the wavelength selective modulator of said each of the plurality of transmit slices;
• and
• a scanning detector disposed along the transmit bus optical waveguide at a location between the optical supply input and the plurality of transmit slices, the scanning detector configured to provide controlled diversion of a portion of light having a mapping wavelength from the transmit bus optical waveguide, which correspondingly causes a drop in optical power detected by one of the photodetectors within a given one of the plurality of transmit slices that receives the drop portion of light that has a wavelength equal to the mapping wavelength, which indicates that the wavelength selective modulator of the given one of the plurality of transmit slices has a resonance wavelength equal to the mapping wavelength.

A method for mapping resonance wavelengths of wavelength selective modulators across an optical transmit macro of an electro-optical chip, comprising:

• conveying a plurality of wavelengths of continuous wave light through a transmit bus optical waveguide that extends through a plurality of transmit slices of an optical transmit macro of an electro-optical chip, wherein each of the plurality of transmit slices includes a wavelength selective modulator and a photodetector, the wavelength selective modulator optically coupled to the transmit bus optical waveguide, the wavelength selective modulator configured to modulate a selected one of the plurality of wavelengths of continuous wave light that is conveyed through the transmit bus optical waveguide, the photodetector optically connected to receive a drop portion of light from the wavelength selective modulator within a same one of the plurality of transmit slices;
• operating the wavelength selective modulator in each of the plurality of transmit slices to modulate said selected one of the plurality of wavelengths of continuous wave light that is being conveyed through the transmit bus optical waveguide;
• conveying the drop portion of light that is currently being modulated by the wavelength selective modulator in each of the plurality of transmit slices to the photodetector within said each of the plurality of transmit slices;
• operating the photodetector within each of the plurality of transmit slices to generate a photocurrent corresponding to the drop portion of light that is currently being received by said photodetector;
• and
• operating a scanning detector to divert a portion of light having a mapping wavelength from the transmit bus optical waveguide to cause a drop in optical power detected by a given one of the photodetectors that receives the drop portion of light that has a wavelength equal to the mapping wavelength, wherein the drop in optical power detected by the given one of the photodetectors indicates that the wavelength selective modulator that provided the drop portion of light to the given one of the photodetectors has a resonance wavelength equal to the mapping wavelength.