Positioning and localization of two-wavelength
interferograms for wavefront reconstruction 
with volume holographic media

Abstract

This work studies both theoretically and experimentally the formation of the contour interference patterns generated by a two-wavelength real-time holographic interferometer. The resulting contour interference fringes are due to the intersection of the measured surface with parallel, equally spaced planes of constant elevation. The theoretical analysis describes how the spatial frequency of the elevation planes, their angular position, and the localization of the fringes depend on parameters of the optical setup. A theoretical model for fringe localization is developed and confirmed by the experiments, showing a strong dependence of the interferogram position on the slope of the studied surface. Due to the thick Bi(12)TiO(20) crystal employed as the storage medium the Bragg selectivity of the holographic readout is also considered.

Design, construction, and performance of a real-time holographic refractometry prototype for liquid analysis

“…More details about twolaser holographic setups can be found elsewhere. 25,29 Both lasers are of the same model with emission wavelength centered at ∼662 nm. By properly selecting the currents in the drivers the lasers were tuned in order to provide the synthetic wavelength λ S = 788.8 ± 0.3 μm, which corresponds to a wavelength difference of λ 1 −λ 2 = 0.56 nm.…”

Real-time, Multi-wavelength Holographic Recording in Photorefractive Volume Media: Theory and Applications

“…On the other hand, in figure 12b, when the interferogram of the right half of the surface is focused, the contour fringes of the left half cannot be visualized. The arrow shows the limit between the negative and the positive slope of the surface (Barbosa, 2010).…”