Ultrahigh resolution absolute Cartesian electronic autocollimator

摘要

The development of a compact, ultra-high resolution, electronic autocollimator with excellent readout stability, linearity, and coordinate orthogonality is presented. This optical metrology tool relies on new advances in Cartesian optical encoders based on pattern recognition technology. Readout instabilities characteristic of conventional electronic autocollimators whose lateral effect photodetectors and operational amplifiers exhibit temporal and thermal drifts, are absent in this new technology. An autocollimator with a form factor similar to conventional alignment telescopes has been demonstrated with an angular resolution of 0.02 arcseconds peak-to-peak and less than 0.01 arcseconds rms. Various optical metrology applications for the laboratory and for space flight, including cryostatic ones, are described.