부산대학교 도서관

A gain-coupled high-power low-RIN $1.55~\mu \text{m}$ single-mode distributed feedback (DFB) laser with a 6- $\mu \text{m}$ -wide ridge waveguide is demonstrated based on an optimized double trench ridge waveguide structure. Gain-coupling mechanism is implemented by carrier-injection gratings. The impact of the doping concentration and thickness variations in the p-InP spacer layer on the carrier density ripple within the active region is investigated to achieve a large gain-coupling coefficient. The fabricated DFB laser exhibits a ~ 220 mW kink-free output power with a relative intensity noise (RIN) below −166 dB/Hz at 25°C. The side-mode suppression-ratio (SMSR) is about 60 dB and the far-field full-width-at-half-maximum (FWHM) divergence angles are $10^{\circ }\times 20^{\circ }$ .