HIGH-INVERSION LASER DEVICE HAVING AN IMPREGNATED FLASHTUBE JACKET, AN ULTRAVIOLET ABSORBING FILTER BETWEEN THE LASER ROD AND THE FLASHTUBE AND A FILTER WITHIN THE LASER ROD

A laser apparatus for reaching a high-inversion level by the reduction of transverse depumping mechanisms, having a laser rod optically coupled to a pumping flashlamp capable of producing lasing action. The inversion level of the laser rod is improved by a filter for absorbing radiation within the lasing wavelength while being substantially transparent to the pumping wavelength. A portion of the filtering system is located inside the laser rod while another portion may be in the quartz envelope of the flashlamp or in other locations, as desired.