40-Gbps direct modulation of 1.55-µm AlGaInAs semi-insulating buried-heterostructure distributed reflector lasers up to 85°C

1.55-mum AlGaInAs semi-insulating buried-heterostructure distributed reflector lasers with 75-mum-long active region achieved very high slope values of relaxation oscillation frequency of 4.5 (25degC) and 3.5 GHz/mA1/2 (85degC), which realized 40-Gbps direct modulation up to 85degC.