Gain-Coupled Wide-Ridge-Waveguide High-Power 1.55µm Single-Mode DFB Laser

Gain-coupled 1.55
$\mu \mathrm{m}$
single-mode DFB laser with
$6-\mu\mathrm{m}$
-wide ridge-waveguide is demonstrated based on a double trench ridge waveguide structure. The fabricated laser exhibits over 100 mW kink-free output power and FWHM divergence angles of 11°×21°.