Development of the $\mathsf{2.8}\mu \mathsf{m}$ emission doubly shifted Raman laser using stimulated Brillouin scattering in a cascaded cavity

Abstract

A doubly shifted Raman laser using ${\mathrm{CH}}_4$ gas has been developed for $2.8\mathrm{\mu m}$ generation, pumped by a Nd∶YAG laser with $65.5\mathrm{mJ}$ at $17\mathrm{ns}$. A dichroically coated meniscus-type lens is modified to utilize the backward stimulated Brillouin scattering and backward Stokes beams from a previous laser design [Appl. Opt. 46, 5516–5521 (2007)]. A maximum output energy of $4.76\mathrm{mJ}$ at $2.80\mathrm{\mu m}$ wavelength has been achieved in the cascaded resonator. A maximum conversion efficiency of 8.9% has been achieved at a ${\mathrm{CH}}_4$ gas pressure of $600\mathrm{psi}$. The obtained spatial beam profile is quite smooth, and its output pulse width is $10\mathrm{ns}$.

© 2008 Optical Society of America