cw optically pumped molecular iodine laser

Laser oscillation on several I2 BO+u (v′=43, J′=12 and 16) →X1Σ+g(v″?9, J″=11, 13, 15, and 17) transitions is observed. The unique feature of this laser is that it is excited by a continuous-wave optical pump, single-longitudinal-mode 514.5-nm radiation from an Ar+ laser, and that it oscillates in a single (v′=43, v″) band for as long as 200 msec. Conversion efficiency of 0.14% with a maximum output power of 3 mW is achieved. Single-pass gain is observed to be 3±1% for the strongest transition. Thresholds of 100 mW and 1 W are observed for single-longitudinal-mode and multimode pumping, respectively. Some 30 laser transitions are observed, spanning nearly an octave of frequency from 570 to 1027 nm.