High-pressure, high-efficiency operation of a chemical oxygen-iodine laser

High-pressure subsonic mode operation of a chemical oxygen-iodine laser (COIL) was demonstrated. Singlet delta oxygen generated by a liquid-jet type singlet oxygen generator (SOG) was directly utilized in the laser cavity, without supersonic expansion. The operating pressure in the laser cavity was 0.80 kPa (6.0 Torr). Cooled nitrogen gas was added to the singlet oxygen flow to enhance the output power. An output power of 448 W was obtained for a chlorine input rate of 19.7 mmol/s. This is equivalent to a chemical efficiency of 25.0%, and it is comparable to the highest reported chemical efficiency of COIL using nitrogen as the buffer gas. The obtained value of specific energy of 3.5 J/liter, is more than fivefold higher than that for our supersonic COIL device. (C) 1999 American Institute of Physics. [S0003-6951(99)05746-0].