Patent ID: 7633673

Claim:
A mid-infrared light source, comprising: a multiplexer operable to combine a first laser signal and a second laser signal to generate a first optical signal, the first optical signal comprising one or more wavelengths; a gain fiber coupled to the multiplexer and operable to receive at least the first optical signal, the gain fiber comprising a first waveguide structure; a second waveguide structure coupled to the gain fiber and operable to wavelength shift at least one wavelength of the first optical signal to a longer wavelength optical signal, the longer wavelength optical signal comprising a wavelength in the range of 1.7 microns or more, the second waveguide structure comprising a wavelength shifting fiber coupled to a nonlinear element, wherein the wavelength shifting fiber operates to wavelength shift the at least one wavelength of the first optical signal to a second optical wavelength and the nonlinear element operates to wavelength shift the second optical wavelength to the longer wavelength optical signal, and wherein the wavelength shifting fiber is substantially different than the nonlinear element.