Precision machined metal mirrors are produced in this Laboratory for use in industrial laser applications. The machining geometry adopted uses a single diamond tool in a high speed flycutting disc on an air-bearing spindle. The tool removes material from a slowly rotating workpiece mounted on a pressurised oil bearing. Plane, cylindrical and spherical surfaces have been machined on aluminium alloy, copper, brass and beryllium copper blanks. These are used as laser cavity, polygonal and beam handling mirrors for use with high power CO2 lasers. A machine which produces mirrors up to 200 mm daimeter is in regular use and 660 mm capacity machine is undergoing trials. Typical plane mirrors are flat to within half a fringe in 30 nun (6328 Å) with a surface roughness of ~100 Å (CLA). The spatial frequency power spectrum obtained from laser scattering measurements is used to identify the sources of vibration in the machining system. This paper discusses machine design parameters, operating and alignment techniques and reports the performance of the mirrors.

Date Published: 16 December 1976
PDF: 8 pages
Proc. SPIE 0093, Advances in Precision Machining of Optics, (16 December 1976); doi: 10.1117/12.955114

Published in SPIE Proceedings Vol. 0093:
Advances in Precision Machining of Optics
Theodore T. Saito, Editor(s)