engleski

Development of a modular laser displacement interferometer

This paper presents the design and development of a modular laser displacement interferometer. Mechanical setup was designed using widely avaliable components, but since no commercial systems specialized for processing interference signals were avaliable, the system for this purpose was developed from basic electronic components. Entire development process is presented, starting with calculation of needed characteristics for operational amplifier and photodiode. Using simulations, optimal components for the system were selected and during laboratory experiments parts were tested individually, assembled in electronic circuits and finally intergrated into an assembled version of the laser interferometer prototype. Developed prototype has the ability to detect the both the direction and the amount of displacement. Its repetability was found to be within a single half-wavelenght (≈ 300 nm), while its absolute accuracy was determined to be within ± 1, 5 μm over 180 mm of travel, based on a comparison measurement with a commercially available interferometer.

laser interferometer ; interferometer fringe detection ; signal processing

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