2-PHOTON BISTABLE SWITCHING OF AN OPTICALLY PUMPED ATOMIC NEON RAMAN LASER

Two cw Raman lines at 603.0 nm (2p(2) --> 1s(4)) and 659.9 nm (2p(2) - -> 1s(2)), generated when cw dye-laser radiation is mode matched to th e 588.2-nm (1s(5) --> 2p(2)) transition of Ne I in a commercial He-Ne laser cavity, can both show optically bistable switching simultaneousl y with the pump beam. A theoretical treatment based on a semiclassical three-state Raman laser model is used to qualitatively reproduce the experimental observations and to identify the mechanisms that produce the experimental signature. Important features of the Raman gain are c haracterized. These, in combination with the phase-shift properties of the pump and Raman fields, are used to explain the switching behavior .