Phase matching of four-wave interactions of SRS components in birefringent SRS-active crystals

A new method has been proposed for achieving wave vector matching in four-wave interactions of frequency components upon SRS in birefringent SRS-active crystals. The method ensures anti-Stokes wave generation and enables a substantial reduction in higher order Stokes SRS generation thresholds. Phase matching directions in BaWO₄ SRS-active negative uniaxial crystals and SrWO₄ SRS-active positive uniaxial crystals have been found in the wavelength range 0.4 — 0.7 μm.