Tunable laser architecture

A tunable laser architecture comprising:

• a semiconductor gain chip having a first end and a second end, wherein a high reflectivity coating is disposed on the first end of the semiconductor gain chip;
• a photonics chip configured to be in optical communication with the semiconductor gain chip, such that the second end of the semiconductor gain chip is associated with a first end of the photonics chip, the photonics chip comprising:
• a laser input in optical communication with the semiconductor gain chip;
• a main waveguide in optical communication with the laser input;
• an optical splitter in optical communication with the main waveguide;
• a first branching waveguide in optical communication with the optical splitter, wherein the first branching waveguide is configured to be in optical communication with a laser output;
• a second branching waveguide in optical communication with the optical splitter;
• a first Vernier ring in optical communication with the first branching waveguide;
• a second Vernier ring in optical communication with the second branching waveguide;
• and
• a monitor pathway waveguide in optical communication with the first Vernier ring and the second Vernier ring, wherein the monitor pathway waveguide is configured to be in optical communication with a monitor photodetector;
• wherein the optical splitter is configured to split power of an incoming laser from the main waveguide between the first branching waveguide and the second branching waveguide and the first Vernier ring and second Vernier ring have different free spectral ranges.