Patent ID: 8462426
Filing Date: 2013-06-11
Classification: H01S

Abstract:
1. A method of producing a high-powered narrow-linewidth laser output by reducing the stimulated Brillouin scattering effect, comprised of: providing a double clad gain fiber having an outer and an inner cladding, a Brillouin gain spectral width, and a Yb-doped core such that most of the laser ht is contained in the core, said gain fiber having an input end, an output end, and a middle section, and the core of said gain fiber being acoustically homogeneous; pumping said gain fiber at the input end by a pump source to produce population inversion; providing a first seed light source and a second seed light source, with each having a respective wavelength; said first seed light source having a linewidth on the order of the Brillouin gain spectral width or less, an input power level, and a wavelength separation of approximately 20 nm or greater from the wavelength of said second seed light source; said second seed light source having higher emission and absorption cross-sections than said first seed light source, an input power level of at least 3 times the input power level of said first seed light source, and a spectral width of at least 3 times the Brillouin gain spectral width at the wavelength of said second seed light source; combining said first and second seed light sources with a wavelength division multiplexer; coupling out unused pump light; optically isolating said first and second seed light sources to prevent damage from backward scattered light; optically combining said first and second seed light sources prior to coupling them into the input end of said gain fiber; and amplifying said first seed light source to provide a high-powered narrow-linewidth laser output of at least 100 W.