Narrow linewidth, low frequency chirping and broad wavelength tunable ring resonator coupled lasers

摘要

A ring resonator coupled laser is described, which has a gain region for creating light radiation, ring resonators for providing a strong mode selection and Vernier effect for wide wavelength tunability, passive waveguides for coupling the light and a pair of reflective mirrors for forming a laser cavity. By combining the ring resonators with the reflective mirrors, a strongly frequency-dependent passive mirror with complex amplitude reflectivity is formed and this ring resonator coupled laser exhibits single longitudinal mode operation with a high side mode suppression ratio, narrow linewidth and reduced frequency chirp. By using two slightly different ring resonators, the wavelength tunability is greatly enhanced. Thus, electro-optic effect is preferred for high speed wavelength tuning in the ring resonator coupled laser.