Distributed reflector lasers integrated with passive grating region by using lateral quantum confinement effect

By using a lateral quantum confinement effect, a new type of distributed reflector (DR) laser consisting of a wirelike active section and a passive DBR section with quantum-wire structure was demonstrated. As a result, a low threshold current density J_th=320 A/cm² (I_th = 15.4 mA) was obtained for a mesa-stripe width of 20 μm, an active section length of 240 μm and a passive DBR section length of 440 μm. A strong asymmetric output ratio from the front to the rear facet of 28, which is inherent in DR lasers, was also achieved.