Y-Branch Surface-Etched Distributed Bragg Reflector Lasers at 850 nm for Optical Heterodyning

This letter presents a monolithically integrated dual-wavelength source at 850 nm suitable for use in optical heterodyning. The device consists of two surface-etched distributed Bragg reflector (DBR) lasers, a Y-branch coupler, and a curved waveguide outcoupler. The Y-branch coupler and curved outcoupler are fabricated with the same epitaxial material as the DBR lasers, enabling operation as a semiconductor optical amplifier. The spectral characteristics and frequency stability of the two wavelength lasers are reported.