Recently, high-power broad-area laser diodes based on GaN with output powers beyond 1 W have become available. However, their broad spectral emission limits their applicability. Due to a lack of internal grating technology for GaN devices, narrowband emission with several hundreds of milliwatts in the blue-green spectral range has not been achieved with laser diodes thus far. In this work, a high-power external cavity diode laser (ECDL) system at 445 nm is presented. The system is based on a commercially available broad-area GaN laser diode and a surface diffraction grating in Littrow configuration for optical feedback. Using this configuration an output power of 400 mW with a reduced spectral emission bandwidth of 20 pm (FWHM) with a side-mode suppression ratio larger than 40 dB is obtained. With the above presented optical output power and narrowband laser emission at 445 nm, the ECDL is well suited as a pump light source for nonlinear frequency conversion into the deep ultraviolet spectral range.

Date Published: 20 March 2015
PDF: 6 pages
Proc. SPIE 9382, Novel In-Plane Semiconductor Lasers XIV, 93820P (20 March 2015); doi: 10.1117/12.2076926

Published in SPIE Proceedings Vol. 9382:
Novel In-Plane Semiconductor Lasers XIV
Alexey A. Belyanin; Peter M. Smowton, Editor(s)