Compact Watt-class visible light sources using direct frequency-doubled edge-emitting diode lasers

摘要

Compact laser light sources in the visible spectral range emitting several Watts are required for display technology, sensor systems and material processing. Second harmonic generation (SHG) using highly brilliant edge emitting infrared lasers is a promising way to fill the spectral gap of directly emitting semiconductor lasers. Newly developed distributed Bragg reflector (DBR) tapered lasers allow a very efficient SHG due to their extraordinary brightness. On an optical bench more than 1 W power at 488 nm was obtained by directly doubling the laser light with a 5 cm long PPLN crystal. Using hybrid integration on a micro-optical benches we now achieved 0.5 W power at 488 nm with a 2.2 cm long PPLN crystal.