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Interference sensor for ultra-precision measurement of laser beam angular deflection
1Faculty of Mechatronics, Institute of Metrology and Biomedical Engineering, Warsaw University of Technology, Sw. A. Boboli 8 Str., Warsaw 02-525, Poland.
Abstract:
A new interference sensor for ultra-precise measurement of laser beam angular deflection is proposed. The angular tilt of the measuring device, in relation to the beam axis, can also be measured. The theoretical basis of the angle evaluation presented is based upon analyzing the fringe period, as well as the suggested optical setup and design of the device. Calculating algorithms for the evaluation of the beam angle change, the influence of the fringe phase on angle measurement, and the metrological feasibilities are also detailed herein. The main source of measurement errors is explored, and the influence of the sensor's positioning procedure in relation to the laser beam on the repeatability of the processing function is statistically analyzed. The results show that the sensor resolution reaches 25 nrad with an accuracy better than 1% in the measuring range 350 µrad. Finally, the potential applications of the interference sensor are described.
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