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A High Efficient Dual-Wavelength Mid-Infrared Optical Parametric Oscillator Pumped by the Raman Fiber Oscillator

In this paper, a novel high efficient dual-wavelength mid-infrared optical parametric oscillator (OPO) was demonstrated, which was pumped by a dual-wavelength Raman fiber oscillator for the first time. The adoption of oscillator structure reduced the waste of power, increased Raman pump power and promoted its frequency conversion. The dual-wavelength pump source was fixed at 1070 nm and 1120 nm and the Raman conversion efficiency was greatly enhanced from 26.7% to 72.1%. The high Raman efficiency and low Raman threshold enabled the Raman laser to build optical parametric oscillation easily and the pump-to-idler conversion efficiency of Raman laser improved greatly from 4.2% to 13.3%. The generated dual-wavelength mid-infrared laser was fixed at 3272 nm and 3663 nm, with a maximum power of 6.87 W, indicating a 13.9% pump-to-idler conversion efficiency. The highest mid-infrared output power generated by optical parametric oscillation of Raman laser was also achieved, which is almost ten times than before.