Performance of high-voltage axially pulsed CO2lasers

A parametric investigation of high-voltage axially pulsed CO2lasers was performed. The parametric variables were tube diameter, discharge voltage, discharge capacitance, and gas mixture. The output energy per unit discharge length increased linearly with tube diameter for laser bores greater than 5 cm. Volumetric scaling was obtained with 2.5-cm and 5-cm bore lasers. A maximum energy density of 4.8 mJ/cm3was obtained in the 2.5-cm bore laser at a total pressure of 90 torr. A maximum energy per pulse of 287 J was obtained with a 15-cm-bore 10-m-long laser. For all lasers and gas conditions the output energy increased as the applied voltage was increased until an arc discharge occurred. At maximum output energy the ratio of applied electric field-to-total gas pressure was approximately 15 V/cm-torr. The optimum energy-storage capacitance increased with tube diameter.