Improvement of accuracy of measurement of wedge angle of plates in holographic reversible shearing interferometry
The study aims to improve the accuracy of interferometric methods for measuring small wedge plates by increasing the sensitivity of the method. Relevance is determined by the growing research needs to metrological characteristics of the angular measures, quality plane-parallel and wedge-shaped plates that are used in modern interferometers, laser and other opto-electronic technology. In the introduction it es analyzed existing optical methods for measuring the wedge plates and methods to improve measurement accuracy. In the main part the proposed new method of improving is proposed the accuracy of measurement of transparent wedge plates in holographic reversible shearing interferometry. The technique allows to reduce the relative error of measurement due to the exclusion of systematic error component caused by the optical aberrations of the instrument, as well as increasing the number of interference fringes in the interference patterns formed by wedge-shaped plate. It is shown that due to the sequential processing of a pair of double the amount of interference fringes is achieved by reducing the measurement error is two-fold compared with conventional interferometric methods. Experimental results of testing the proposed method to measure the wedge angle of the wedge plate. The developed method can be used for precise measurements in quality control of transparent plane-parallel and wedge-shaped plates.