Emission in the Region 4000 to 7000 Å Via Four-Photon Coupling in Glass

Abstract
Four-photon stimulated scattering has been observed in borosilicate glass under high-power 5300-Å picosecond-pulse excitation. Parametric emission is generated from 4000 to 7000 Å from filaments formed in the glass, the wavelength depending on the emission angle.