Red VCSEL for automotive applications

Abstract

In this paper we discuss the problems of the AlGaInP material system and its consequences for the laser applications in vertical-cavity surface-emitting lasers (VCSEL). The epitaxial and technological solutions to overcome at least parts of the inherent problems were presented. Measured power-current curves of 660nm AlGaInP-based oxide-confined VCSEL are compared with calculated data by a cylindrical heat dissipation model to improve heat removal out of the device. Pulsed lasing operation of a 670nm VCSEL at +120°C heat sink temperature is demonstrated, where we exceeded 0.5mW and at +160°C still 25μW output power were achieved. We also studied the modulation bandwidth of our devices and achieved 4GHz and calculations lead to a maximum possible intrinsic -3dB frequency of 25GHz.