85/spl deg/C investigation of uncooled 10-Gb/s directly modulated InGaAsP RWG GC-DFB lasers

The 10-Gb/s directly modulated performance of InGaAsP ridge waveguide (RWG) gain coupled (GC) DFB lasers is investigated up to 85/spl deg/C. At room temperature, devices have relaxation oscillation frequencies f/sub relax/ greater than 20 GHz and damping /spl Gamma/ greater than 100 GHz, f/sub relax/ is greater than 6 GHz at 85/spl deg/C. Constant output power or extinction ratio are possible from 25/spl deg/C to 75/spl deg/C chip temperature, with open eyes observable up to 85/spl deg/C. Back-to-back transmission measurements in a Nortel Networks OC-192 system show error free transmission of a 2/sup 23/-1 pseudorandom bit sequence at 83/spl deg/C.