George N. Steinberg

Unstable resonators for annular gain volume lasers

Experimental performance of several different unstable resonators with annual cylindrical mode volumes is reported. Laser output beam quality and its sensitivity to resonator component misalignments and figure errors are described. Near diffraction-limited beam quality was obtained from an annular cylindrical He-Xe laser employing a half-symmetric unstable resonator with an intracavity axicon.

New Developments in Interferometry

This article is based on a series of talks presented by personnel of The Perkin-Elmer Corporation at a symposium held in September 1967 and thereafter brought up to date for inclusion in the APPLIED OPTICS feature discussing Interferometry vs Spectroscopy.

Rapid optical figuring of aspherical surfaces with plasma-assisted chemical etching

Programmed motion of a tool which removes material by plasma assisted chemical etching (PACE) gives controlled, deterministic figuring. The process has been automated to correct arbitrary figure errors on aspheric surfaces directly from the measured surface data. A system is now operating for figuring aspheric surfaces up to 0.5 m diameter. PACE can greatly reduce the time and cost of figuring large optics by its rapid convergence to the final figure requiring only two to three measurement/figuring cycles to reach 1/50 wave surfaces. PACE intrinsically smooths high frequency roughness with material removal leaving a surface free of subsurface damage