Operating characteristics of a transverse-excited 16 microns CO2 laser with profile electrodes and UV-preionization

A 16 micron CO2 electric-discharge pumped gas laser also excited by a 10 micron CO2 gas laser is described. Population inversion can be achieved at 16 microns by an electrical discharge, by transferring half of the (00/0/1) population to the (02/0/0) level using stimulated emission, or by retaining a low thermal (01/0/0) population with a low background gas temperature. Experimentation was performed with a 16 micron laser pumped by a 9.4 micron laser. Thyratron switches were included, together with a grating tunable oscillator and pulses up to 1.7 J. All vibrational modes of CO2 are excited at 16 microns. Gas heating was found to limit the discharge excitation energy load. The short build-up time of the 16 micron radiation permitted deactivation and fast inversion relaxation, a factor which might be ameliorated by synchronization of a pump laser to temporal coincidence with the 16 micron laser.