Michael W Barrett

US Patent:

50654055, Nov 12, 1991

Filed:

Jan 24, 1990

Appl. No.:

7/469332

Inventors:

Peter Laakmann - Seattle WA
Stanley R. Byron - Seattle WA
Michael W. Barrett - Seattle WA

Assignee:

Synrad, Incorporated - Bothell WA

International Classification:

H01S 308

US Classification:

372 92

Abstract:

An improved sealed-off RF-excited gas laser and method for its manufacture. The resonator section of the laser consists of four optically reflecting longitudinal walls which define the laser bore and plasma section. A concave mirror is mounted on one end of the resonator and a flat or concave output coupler is mounted at the other end. The laser resonator operates in a non-waveguide non-free space mode utilizing wall reflections. Artifacts are introduced at the optically reflecting walls to define a stable oscillatory axis and mode structure by favoring the establishment of stable reflection points along the length of the walls. These artifacts are created by carefully defined bends and tapers in some of the walls to create high mode purity, stability and relatively uncritical optical alignments. Manufacturing methods are disclosed to speed up passivation of the sealed enclosure by internal preexposure of the sealed envelope to oxygen-helium plasmas created at different temperatures, pressures and peak power than seen in the subsequent laser operation.