Single and double quantum well lasers with a monolithically integrated passive section

Single (SQW) and double (DQW) quantum well composite cavity GaAs/AlGaAs lasers with an integrated passive section were fabricated and compared. Si implantation was used for partial quantum well disordering in the passive section. Implanted DQW lasers with a 2.6-mm-long cavity had threshold currents of 26.3 mA compared to 33 mA for implanted SQW lasers. The measured resonant absorption in the passive section showed an exponential roll-off in agreement with Urbach’s law. The characteristic energy E0 associated with Urbach’s law was 6 meV for untreated SQW and DQW lasers and ≊11 meV for implanted SQW and DQW lasers.