Holographic methods for regulating the sensitivity of interference measurements for transparent media diagnostics

Reduction of the error in measuring the wedge angle of transparent plates in holographic reverse-shearing interferometry

“…To form such a fringe (for example, a bright one) in the right interferogram, one can change the inclina tion of one of the light beams, (7) or (8), at the output of interferometer 8 (Fig. 1a).…”

“…Obviously, the factor should be zero for these waves (which are dif fracted into the first and zero orders). In this case, the right and left interferograms will be formed by the pair of waves diffracted into zero (for wave (8)) and first (for wave (7)) orders in holograms (4) and (5):…”

“…The sensitivity of a measurement tool is the ratio of the change in the output signal to the variation in the measured value responsible for this change [6]. When determining the measurement sensitivity in interferometry, the output signal is considered to be the spatial modulation of illuminance, which is an interference pattern tuned to an infinitely wide fringe [7,8]. In this case, the measurement sensitivity (as applied to wedge angles) is proportional to the ratio of the fringe frequency in the formed interferograms of a wedge shaped plate to the wedge angle.…”