A wavelength tunable and integrated ultra-narrow linewidth DBR semiconductor lasers

We proposed an integrated semiconductor laser scheme that combines an ultra-high Q silicon nitride microresonator with a DBR semiconductor laser, resulting in a tunable ultra-narrow linewidth laser. The experiment achieves tuning within the wavelength range of 1554.2-1557.15nm (about 370GHz), being almost ten times larger than that of reported DFB scheme. Moreover, the sidemode suppression ratio is low to 52dB with a ultra-narrow linewidth about 6.6kHz. It needs the joint adjustment of DBR operating current, coupling of the high-Q silicon nitride external cavity. These results can be applied in fields such as dense wavelength division multiplexing systems and integration LiDAR System.