Stimulated four-photon mixing in glass fiber waveguides in the spectral range 0.4–1.8 μ

The Stokes–anti-Stokes components were generated in few-mode fiber waveguides pumped by a neodymium garnet laser (λ_p =0.532 and 1.064 μ). Such generation was attributed to stimulated four-photon processes. Phase matching in the waveguides was achieved by compensation of the material dispersion with the intermode dispersion. The emission frequency could be varied by varying the diameter of the waveguide core. When the pump wavelength was λ_p =1.064 μ, the generation of light in the Stokes region was observed at wavelengths λ right up to 1.8 μ, whereas in the anti-Stokes region this occurred right up to 0.4 μ.