Diode Pumped Cesium Laser

We have demonstrated a Cs vapor laser with diode laser pumping and have achieved a slope efficiency of 41{\%} and overall optical efficiency better than 32{\%}. A narrowband diode laser operating at 852 nm pumps the 6$P_{3/2}$ state (D$_{2}$ line) which is then rapidly quenched to the 6$P_{1/2}$ state by an ethane buffer gas. This creates a population inversion between the 6$P_{1/2}$ and 6$S_{1/2}$ states and lasing at 894 nm. The experimental set-up consisted of an injection seeded SDL-8630 diode laser pump and a Cs vapor cell positioned inside a stable laser cavity. The laser cavity was longitudinally pumped through the input cavity mirror. This mirror had a concave radius of 20 cm with 90{\%} transmission at 852 nm and about 99{\%} reflectivity at 894 nm. A series of flat output mirrors were used with reflectivities for both 894 nm and 852 nm ranging from 20{\%} to 90{\%}. The optimal output coupler reflectivity was 30{\%} at 894 nm. The length of the laser cavity was 16.5 cm. The pump laser had a maximum output power of 500 mW at 852 nm with FWHM of less than 1 MHz. The Cs vapor cell was 2.5 cm long with Brewster windows at both ends. It was filled with metallic cesium and 100 Torr of ethane at 20 $^{o}$C and was placed inside an oven. We acknowledge support from the Air Force Office of Scientific Research and the National Science Foundation under Grant No. 0355202