Fast axial flow carbon dioxide laser

Abstract

A fast axial flow carbon dioxide laser has a laser head arranged to provide multiple folding of the laser beam into two, four or more linear passes. The construction of the head is such as to provide for generating either one laser beam or a pair of beams, by adjustment of optics. Located centrally in the laser head is a single exhaust manifold for exhausting all of the axially flowing gas from a series of colinear and spaced parallel discharge tubes on opposite sides of the exhaust manifold. Gas flow is from two outer inlet manifolds toward the central exhaust manifold, so that optics of the system are isolated from contamination and from the hot exhaust. Adequate distribution of gas within each discharge tube is assured by the manner in which the flowing gas is directed into the discharge tubes. Special mirror mountings in the laser head provide for a highly stable operation under changing temperatures, primarily due to the use of a graphite fiber/composite tube supporting structure having near-zero longitudinal thermal expansion. For the fold mirrors there is included a mirror alignment and cooling system which provides for easy removal of each mirror for cleaning and replacement, without affecting mirror alignment.