US Patent 10236661 Wavelength variable light source

A wavelength variable light source includes a housing, a heat sink disposed in the housing, an excitation light source disposed on the heat sink and configured to output excitation light, a gain medium disposed on the heat sink and including an active layer and a lower DBR, a MEMS mechanism including a movable film facing the gain medium via a gap, disposed on the gain medium, and configured to control the gap, an upper DBR provided in the movable film and configuring a resonator together with the lower DBR, a reflector configured to reflect the excitation light output from the excitation light source toward the gain medium in the housing, and a window formed in the housing and configured to transmit light output from the gain medium.