A Widely Tunable InGaAs/InGaAsP DBR Laser for Gas Detection

We demonstrate a widely tunable distributed Bragg reflector (DBR) laser, in which the DBR section was realized by using butt-jointed InGaAsP $(\lambda = 1.46 \mu m)$ material. By adjusting the DBR current, a widely tuning range of 10.3nm with 21 consecutive channels is obtained at room temperature (RT) for three-section device. With the help of the heat sink temperature, the tuning range is expanded to 11.7nm. A side mode suppression ratio (SMSR) of higher than 30dB is obtained for all channels. It is a promising light source for methane detection. This experiment also demonstrates that the butt-jointed active-passive integration technology developed for the InGaAsP quantum-wells (QWs) can be successfully applied in the InGaAs QWs.