High power flowing gas laser with profiled electron beam excitation

Abstract

A high power, cw, high pressure, electrically excited flowing gas laser is disclosed wherein a laser excitation transverse to the direction of gas flow is initiated by an electron beam perpendicular to the gas flow direction. The electron beam has a cross-sectional area conforming substantially to that of the excitation region and is especially profiled to have a cross-sectional electron density which varies as a function of distance along the direction of gas flow from substantially a minimum value at the upstream and downstream extremities of the excitation region to a maximum value approximately midway along the excitation region. This profiling, which may be achieved by tapered width apertures in either an electron beam window support member or in an electron gun grid, provides an appropriate heat input to the laser gas to minimize gas density variations in the excitation region and thereby optimize the beam quality of the generated laser beam.