Hamamatsu develops narrow-bandwidth and stable-wavelength operation of spatial beam-combining high-power LD stack configuration using a single VBG (bandwidth 8.4-fold reduction) at first in world, which might lead to the development of excitation LD light source that improves all solid-state lasers’ performance.
Hamamatsu, Japan – April 15, 2015 – Hamamatsu Photonics K.K. has developed the -wavelength beam-combining laser diode (LD) in narrow spectral bandwidth less than one eighth. This development was achieved by controlling the wavelength from two high-power LD stacks at the same time using a stripe mirror and single plane type VBG※(Volume Bragg Grating). This might lead to the development of excitation LD light source that improves all solid-state lasers’ performance.
Results of this research was published in the electronic version of Applied Physics Express (APEX) Online on April 14, and will appear in the May issue of the publication. In addition, the oral presentation will be given in an international conference on the laser, OPIC 2015 (OPTICS & PHOTONICS International Congress) on April 23.
Optical devices with a Bragg grating strongly diffracting the light in a specific direction by periodic slight change in the refractive index inside the photothermorefractive glass with photo-induced refractive index (photorefractive). The light narrow-bandwidth is strongly reflected only in a specific direction, and is almost not reflected at any angle other than the one specified. It improves LD’s horizontal and vertical mode, and realize stable wavelength and narrow bandwidth.