Simultaneous noncollinear stimulated Raman scattering and second harmonic generation in periodically poled lithium niobate

We report the application of periodically poled lithium niobate (PPLN) to perform simultaneous SRS and second harmonic generation (SHG) to improve the wavelength coverage of a soliton self frequency shifted (SSFS) Nd³⁺:YLF laser. The PPLN crystal provides access to very high nonlinear gain coefficients, which are ideal for efficient SRS and SHG frequency conversion. With full incident power at the SSFS wavelengths focussed into the PPLN crystal, the power in the SRS spectrum was measured to be 18 mW across the measurable spectral range, providing a conversion efficiency of 12%.