Isolator for laser optical assemblies

Abstract

An optical assembly isolator and laser system incorporating the same. The isolator attaches to an end of the laser system along the optical axis of the laser system. The isolator includes a flow loop wall, an optical assembly wall, an outer wall connecting the foregoing two walls, and at least one baffle wall included in the volume defined by the outer wall. The flow loop wall and the baffle wall include open first and second apertures, and the optical assembly wall supports an optical assembly. When the isolator is in place on the laser system, the first and second apertures and the optical assembly all align with the optical axis of the laser system. The edges of the first aperture and the flow loop wall can be slanted and oriented with respect to the primary flow through the laser system to induce a small circulation and redirect any entering shock waves and entrained contaminated gas toward the outer wall. The second aperture in the baffle walls can be defined by a surface that extends toward the flow loop wall of the isolator, thereby cancelling shock and expansion waves and dissipating any shock wave energy that enters the isolator from the discharge region of the laser system. This second baffle shape also promotes flow of clean purge gas along the optical axis toward the flow loop and spoils flow of contaminated gas toward the optical assembly. Finally, the isolator can incorporate a purge gas system for tangentially injecting a purge gas adjacent the optical assembly wall and creating a series of circulations that tend to cause the contaminants to be distributed against the inner surface of the outer wall of the optical assembly. If desired, a layer of damping and packing material can be placed against the inner surface of the outer wall for the purpose of damping the shock waves and capturing contaminating particulates.