Tunable laser assembly

A tunable laser assembly comprising:

• a tunable semiconductor laser emitting tunable laser radiation;
• a pump laser;
• a semiconductor optical amplifier (SOA);
• at least one photodetector;
• and
• a planar lightwave circuit (PLC);
• wherein the tunable semiconductor laser, pump laser, SOA, and at least one photodetector are aligned to optical waveguides on the PLC.

A stabilized laser comprising:

• a tunable semiconductor laser emitting tunable laser radiation;
• at least one photodetector;
• a planar lightwave circuit with integrated wavelength monitoring circuit;
• and
• a closed loop controller;
• wherein the tunable semiconductor laser, the at least one photodetector, and the planar lightwave circuit are mounted on a common baseplate;
• and wherein the wavelength monitoring circuit generates a signal that is input to the closed-loop controller and the closed-loop controller stabilizes the absolute wavelength and optical bandwidth of said tunable laser radiation.