Low-threshold tensile-strained InGaAs-InGaAsP quantum-well lasers with single-step separate-confinement heterostructures

The authors studied tensile-strained InGaAs-InGaAsP quantum-well lasers with single-step separate-confinement heterostructures (SCH). They obtained threshold currents below 2 mA at 20 degrees C and below 10 mA at 100 degrees C with indium mole fractions of 0.3 and 0.35 in the active layers. They found that the poorer carrier confinement of the longer wavelength SCH layer lowered the characteristic temperature at high temperatures. A laser with two In/sub 0.35/Ga/sub 0.65/As wells and a 1.1- mu m composition InGaAsP SCH layer produced a 1.6-mA CW threshold current at 20 degrees C and lasing at 120 degrees C. Using this laser, very short lasing delays under zero-bias current over a wide temperature range and 2 Gb/s modulation under zero-bias current at 70 degrees C were achieved.>