In this paper, a novel dual-wavelength (DW) mid-infrared optical parametric oscillator (OPO) pumped by a DW Raman fiber oscillator is demonstrated. The DW Raman fiber oscillator fixed at 1070 nm and 1120 nm was obtained using a homemade linear-polarized 1070 nm fiber laser, a wavelength division multiplexer(WDM), a pair of fiber Bragg gratings (FBGs) and a 35-meter polarization-maintaining (PM) passive fiber. At first, only the 1070 nm laser performed the oscillation process and generated signal laser fixed at 1590 nm and idler laser fixed at 3270 nm. As the pump power continued to grow, more and more power was transferred to 1120 nm laser. When the 1120 nm laser was over 11.04 W, it also built its own optical parametric process independently and generated 1614nm signal laser and 3662 nm idler laser, while the oscillation corresponded to 1070 nm remained the same. The output total DW mid-infrared power reached 4.96 W with a maximum pump-idler conversion efficiency of 9.9%. This scheme was not only easy to complement, but also utilize the backward Raman laser to increase the efficiency. The experiment result shows great potential in spectral regulation and cascaded Raman fiber laser can also be used as the pump source to achieve multi-wavelength midinfrared output.
In this paper, a dual-wavelength(DW) mid-infrared optical parametric oscillator(OPO) pumped by a DW fiber laser based on the stimulated Raman scattering(SRS) effect, is demonstrated. When the pump power satisfied the threshold condition, obvious SRS effect was observed and a DW fiber laser with center wavelengths at 1060 nm and 1113 nm was obtained. The DW fiber laser was injected into a single-period crystal, and the whole process went through four stages. In the first three stages, 1060 nm pump laser achieved parametric oscillation and generated 1602 nm signal laser and 3138 nm idler laser and the conversion efficiency was seriously affected by SRS effect. In the fourth stage, two independent parametric processes were realized, which generated two mid-infrared output at 3131nm and 3580nm with powers of 2.46W and 40mW, respectively. The efficiency characteristics in the four stages were also discussed separately.