Continuous anti-Stokes Raman lasers in a He-Ne laser discharge

Novel continuous Stokes Raman lasers (SRL) and anti-Stokes Raman lasers (ASRL) at wavelengths in the range of 603 to 725 nm have been operated in a He-Ne laser discharge tube, between 1s sublevels of Ne using different 2p levels as intermediate resonances. The required population differences or population inversions between the 1 s sublevels are generated in the discharge under the typical He-Ne laser operation conditions. The Raman lasers are pumped with single-mode radiation from a dye laser or a Ti:sapphire laser. Threshold pump powers as low as 3 mW and output power up to 7 mW for 100 mW pump power have been obtained. The lasers show specific features such as a tunability up to ±100 GHz around the resonance, no oscillation at resonance, a characteristic dependence on the direction of the pump polarization, and strong forward-backward gain profile asymmetries