PULSED ALKALI PUMP LIGHT-SOURCES FOR ND-YAG LASERS

Pulsed are discharges in alkali metal vapours are investigated for use as pump light sources for Nd:YAG lasers. Alkali lamps have a very hig h radiation efficiency and emit strong lines near the laser pump bands . These absorption bands are fitted by the emission spectrum of sodium and potassium lamps by changing the vapour pressure and input power. The spectral radiation distributions of the lamps are measured by a sp ectrograph with a gated OMA system. Ray tracing calculations for a las er cavity are used to evaluate the efficiency of the alkali radiation emission for Nd:YAG pumping. The results show that the excitation effi ciency of the alkali lamps is twice as high as that of usually used ra re gas lamps. For sodium resonance lines the side-on spectral radiance is calculated by a radiation transport model to estimate the pressure and the temperature profile. The results indicate that the alkali vap our lamps could be used as pump light sources with high efficiencies a nd low heat loading of the laser cavity. Copyright (C) 1996 Elsevier S cience Ltd.