16-channel 200-GHz-spacing RW-DFB laser array with low noise and high output power

Abstract

We experimentally demonstrated a ridge waveguide (RW) distributed feedback (DFB) continuous-wave (CW) laser array with high output power, low relative intensity noise (RIN) and narrow linewidth for all 16 channels with 200-GHz-spacing. The ridge waveguide is formed above an offset-quantum-well structure to increase single transverse mode waveguide width to 8-µ;m for higher output power and lower noise. A relatively long cavity length of 800-µm as well as a backup laser technique are introduced to achieve good single mode stability. The fabricated RW-DFB laser array realizes the maximum power over 85 mW, RIN lower than -155 dB/Hz and Lorentzian linewidth below 250 kHz for each channel laser. Besides, the side mode suppression ratio (SMSR) is over 51 dB for all 16 channels. These features can help to boost the application in wavelength dimension multiplexed system.