Design of 1.55 μm High-Power, Narrow-Linewidth and Low-RIN Distributed Feedback Laser

A 1.55 μm high-power, narrow-linewidth and low-relative-intensity-noise (RIN) distributed feedback (DFB) laser is proposed. The laser employs three strained AlGaInAs quantum wells to improve output power and InGaAsP waveguide layer to reduce internal loss and far-field divergence angle. We simulate the performances of the designed DFB laser using PICS3D and Lumerical softwares. The DFB laser with a cavity length of 1500 μm shows a single-mode and kink-free output power of 446 mW with far-field full width at half maximum (FWHM) divergence angle of 13.6°×28°. In addition, the DFB laser achieves a linewidth of down to 10 kHz, and an ultra-low RIN of less than −167 dB/Hz in a wide frequency range.