Mode stability, yield, and wavelength fluctuation improvement of high-power DFB lasers for data center networks

We have effectively showcased improvement in single-mode stability, power reduction, and wavelength yield by utilizing newly developed partially corrugated gratings, introducing anti-reflection coatings at both facets, and optimizing grating region length in high-power DFB lasers. By using a longer grating length at the first section (L_g1 = 353.6-μm) and an active region without grating (L_ng = 500-μm) of a 1-mm long cavity, we have achieved more than 183.81-mW output, 51.59-dB side-mode suppression ratio, and less than 0.2764-nm wavelength variation. The proposed laser achieves exceeds 24% wavelength fluctuation enhancement and below 10% power reduction than the former PCG-DFB with HR/AR-coatings, especially when symmetric λ/4 phase-shifted is implemented into the first grating length. Single-mode operation is confirmed by simulation across random interface transmission phases.