Laser resonator having improved efficiency and beam uniformity and associated method

Abstract

A laser resonator and an associated method are provided which produce a laser beam having a relatively uniform intensity profile following a single pass through a single laser cavity. The laser resonator includes a laser cavity through which a chemical medium flows from an upstream end to a downstream end. The laser resonator also includes a first optical element, typically termed a secondary mirror, for directing an expanding laser beam across the cavity. The laser resonator also includes a second optical element disposed opposite the first optical element relative to the laser cavity. Typically, the second optical element is a set of primary mirrors and, more particularly, a pair of primary mirrors for both collimating and spatially inverting the laser beam relative to the predetermined flow direction of the chemical medium through the laser cavity. Once the expanded laser beam has been collimated and spatially inverted, the laser beam is redirected across the laser cavity. The laser resonator can also include a third optical element, such as a scraper mirror, that receives the redirected laser beam following its propagation across the laser cavity and that forms an output laser beam following a single pass of the collimated laser beam across the laser cavity.