Extremely narrow linewidth (~1 MHz) and high-power DFB lasers grown by MOVPE

A suitable structure of narrow linewidth DFB laser is studied experimentally. By thinning the active layer to around 0-07 µm, controlling KL to 1-0, and improving the geometrical uniformity of active region, the linewidth less than 1 MHz is achieved at an output power of around 20 mW in 1.55 μm DFB lasers with 1-2 mm long cavity length.