Distributed Reflector Laser Integrated with Active and Passive Grating Sections Using Lateral Quantum Confinement Effect

A new type of distributed reflector (DR) laser, monolithically integrated with wirelike active section and passive distributed Bragg reflector (DBR) section, was realized for the first time by using the lateral quantum confinement effect in quantum-wire structure. As a result, a threshold current density as low as 320 A/cm 2 and a strong asymmetric output ratio of the front to the rear facet of 28 were obtained for a 20 µm wide stripe structure. For lower threshold and single-mode operation, a narrow stripe DR laser was fabricated. Threshold current of 7.4 mA and submode suppression ratio (SMSR) of 40 dB at a bias current of 1.2 times the threshold were obtained for a stripe width of 3 µm under room-temperature continuous-wave (RT-CW) condition.