Low thermal expansion polymide buried ridge waveguide AlGaAs/GaAs single-quantum-well laser diode

Abstract

A novel ridge waveguide laser diode has been developed in which the ridge is buried in a newly developed polyimide with a low thermal expansion coefficient close to that of AlGaAs which reduces the thermal stress to the junction and simplifies the wafer processing. A planar configuration, which is suitable for optoelectronic integration and an episide down mount for high-power operation, has been achieved by an etch-back process. Under cw operation, a low threshold current of 15 mA at 25 °C, a characteristic temperature T0 of 145 K, and maximum power output higher than 30 mW/facet have been obtained in a molecular-beam-epitaxial-grown graded-index separate confinement heterostructure single-quantum-well laser emitting at 780 nm.