Monolithic integration of a low threshold current quantum well laser and a driver circuit on a GaAs substrate

Abstract
An AlGaAs/GaAs graded-index waveguide separate-confinement heterostructure (GRIN SCH) laser and a laser driver circuit composed of four GaAs metal-semiconductor field-effect transistors have been monolithically integrated on a semi-insulating GaAs substrate. By introducing the GRIN SCH single quantum well (6 nm thick) structure, the integrated laser has exhibited room-temperature cw operation characteristics with an extremely low threshold current of 15 mA as well as a high quantum efficiency of 50%. Measurements have also shown the conversion ratio of laser output power to input gate voltage of 4.3 mW/V, and the turn-on and turn-off times of the light output of 400 and 900 ps, respectively, demonstrating high sensitivity and fast response performance of the present monolithic laser/driver.