Strongly gain-coupled (SGC) coolerless (-40/spl deg/C/spl sim/+85/spl deg/C) MQW DFB lasers

Single mode operation in a wide temperature range (-40/spl deg/C/spl sim/+85/spl deg/C) has been obtained, from an etched-QW strongly gain-coupled (SGC) distributed-feedback laser at 1.3 /spl mu/m. The SGC lasers exhibit an excellent sidemode-suppression-ratio (SMSR) of around 45-55 dB in continuous-wave operation, and a very good transient SMSR (TSMSR) of more than 35 dB during a gain-switched operation, both are over the entire temperature range. When mounted P-side up, the threshold current is about 12 mA at room temperature and 28 mA at +85/spl deg/C. The output power is more than 20 mW with only 120-mA injection current at +85/spl deg/C.