Integrated Low Jitter Mode Locked Lasers

Integrated mode locked lasers are a compact, highly stable means to generate subpicosecond pulses with extremely small pulse to pulse jitter. These are important elements in next generation optical ADCs, pulsed LIDAR, and high speed transmitters. Integration on a silicon platform has a number of inherent advantages: low cost manufacturing in a high volume CMOS facility, ultralow loss optical waveguides, dispersion compensation using silicon ring resonators, and integration with other elements such as modulators, amplifiers, and optical samplers. The ultralow loss of silicon waveguides is important for operation at 8-12 GHz, where the cavity lengths are on the order of 4 mm long. The low loss is also important for high quality ring resonators, which are important for dispersion compensation and short pulse operation. Today, most mode locked lasers utilize many bulk optic components in the cavity, resulting in high coupling losses and internal reflections. The integration of these elements in an integrated cavity will result in lower loss, higher performance and lower cost. The use of a silicon substrate allows low cost, high volume silicon packaging for improved environmental performance in military environments.