Collimating laser diodes with hybrid optics

Abstract

The aim of our investigation is to transform the divergent laser beam emitted by a high power laser diode (HPLD: 250mW, 807nm) in order to increase the efficiency of a HPLD pumped solid state laser. In general it is difficult to correct and collimate the laser beam, because HPLDs show higher order modes depending on the injection current and the diode temperature. Each mode has its own characteristic wavefront.