Understanding light absorption in random lasers and its distribution within the scattering gain media is a key issue to increase the lasers’ efficiency. Here we compare monodispersed and polydispersed powders of Nd³⁺:YVO₄ and investigate the influence of the powder size distribution on scattering mean free path, absorption volume and, eventually, the lasers efficiency. The highest efficiency is achieved for polydispersed powders and we conjecture that these polydispersed powders, composed of pockets containing small grains trapped between large particles, present locally higher pump power densities than the monodispersed powders. We establish a figure of merit, based on measurable powder parameters, that agrees well with the obtained output power results of the monodispersed and polydispersed samples.

Date Published: 22 February 2018
PDF: 8 pages
Proc. SPIE 10528, Optical Components and Materials XV, 105281U (22 February 2018); doi: 10.1117/12.2290674

Published in SPIE Proceedings Vol. 10528:
Optical Components and Materials XV
Shibin Jiang; Michel J. F. Digonnet, Editor(s)