1.6 µm wavelength GaInAsP/InP BH lasers

1.6μm wavelength GaInAsP/InP buried heterostructure (BH) lasers were fabricated by the LPE technique using an antimeltback layer. A new fabrication process was used in order to prevent thermal damage of the etched wafer for second growth and to promote smooth growth. The low threshold current of 23 mA was obtained for a cavity length of approximately 300μm and a stripe width of
3-5\mu
m. Transverse single-mode operation up to more than three times the threshold was obtained. Room temperature CW operation was also obtained with a threshold current of 28 mA and a differential quantum efficiency of approximately 30 percent. Temperature dependences of threshold current and differential quantum efficiency were measured and explained taking account of intervalence band absorption loss due to the split-off band.