Narrow linewidth multi-wavelength light sources

A light source that produces narrow linewidth multi-wavelength (MW) light, the light source comprising:

• a plurality of gain chips, each of which is configured to generate a light beam and each of which includes a laser cavity;
• and
• a wavelength combiner and reflection chip coupled to the plurality of gain chips and including:
• a plurality of phase control sections, each of which is coupled to a respective one of the gain chips;
• a wavelength division multiplexer (WDM) configured to combine the light beams received from the gain chips, via the phase control sections, into a combined light beam;
• and
• a micro-ring resonator (MRR) based reflector configured to receive the combined light beam from the WDM and generate both a reflection MW light beam and a transmission MW light beam;
• wherein the WDM is configured to receive the reflection MW light beam from the MRR based reflector, separate the reflection MW light beam into a plurality of different wavelengths of light, and provide each of the different wavelengths of light via a respective one of the phase control sections to a respective one of the gain chips;
• and
• wherein the transmission MW light beam generated by the MRR based reflector is the narrow linewidth MW light produced by the light source, or is used to produce the narrow linewidth MW light produced by the light source.