Spectral Characteristics of Narrow-Linewidth High-Power 1180 nm DBR Laser With Surface Gratings

We report narrow-linewidth 1180-nm GaInNAs/GaAs distributed Bragg reflector lasers reaching up to ~500-mW continuous-wave output power at room temperature. The lasers employ surface gratings, which avoided the problematic regrowth and enabled a high side-mode suppression ratio over a relatively large mode-hop-free tuning range. The wavelength tuning rates of 0.1 nm/°C and 1 pm/mA were obtained by changing the mount temperature and the drive current, respectively. The lasers exhibit a narrow emission linewidth (<;250 kHz) even at high output power levels. The side-mode suppression ratio is relatively independent of the power level and remains higher than 50 dB even in the vicinity of the roll-off point. An outstanding temperature stability is provided by good carrier confinement in the GaInNAs/GaAs quantum well. A 2000 h burn-in with constant 1.5 A bias at 20 °C improved the output characteristics slightly and did not reveal any failure among the tested components.