A frequency-multiplexing light source with monolithically integrated distributed-feedback diode lasers

The details of the fabrication and performances of a monolithically integrated frequency-multiplexing light source are presented. The light source consists of six GaAs-GaAlAs distributed-feedback (DFB) diode lasers with different grating periods and passive GaAlAs waveguides. By changing the grating periods by ∼9 Å, the lasers lase with different wavelengths with a separation of ∼20 Å. Laser output beams are guided and collected into a single launching waveguide through bends and confluence regions. The overall differential quantum efficiency of about 0.3 percent is obtained at the launching output terminal.