Operation of a helium-free TEA CO2 laser

A novel and inexpensive excitation circuit based on a single switch and a single source drives helium-free TEA CO2 lasers, mini to conventional types. By varying the partial pressure of either CO2 or N2, the duration (FWHM) and the peak power of the laser pulse (for a system with active volume ∼70 cc) is made to vary by a factor of ∼7 and ∼5, respectively. Although, the multi-mode operation efficiency of this laser is marginally smaller than that of the same laser when operated with conventional gas mixture, its efficiency in TEM00 mode operation has always been found to be higher. This laser can be used wherever a TEA CO2 laser with conventional gas mixture containing helium is used.