Noise filtering in the interference pattern by dynamic holographic recording in photorefractive Bi_12TiO_20 crystals

Abstract

The possibilities of stabilization of the interference pattern by filtration of a random-phase noise caused by vibrations, turbulence, and other local changes in the wave front in interferometric measurements are investigated. Dynamic holographic recording in photorefractive Bi(12)TiO(20) crystals is used. The parameters of the holographic recording are presented for determination of the dynamic range for filtering. Noise filtering takes place in real time and contributes to the enhancement of the contrast and the signal-to-noise ratio of the interference pattern. This results in a considerable increase in the sensitivity and the accuracy of the interferometric measurements.

Multilayer stacking technique for holographic polymer dispersed liquid crystals

“…13 Application of an electric field across the cell modifies Fresnel matrix F jk and reduces to a unity matrix due to an index match between n j and n k hence, for the normally incident wavefront it breaks the condition for interfacial roughness between the alternating LC rich and polymer layers. ͑3͒, in the plane wave traveling through the HPDLC cell and hence add a rms variation in the surface profile of the wavefront.…”

Compensation Method for Phase Fluctuation in Holographic Data Storage

“…[5][6][7] The significant effect of phase fluctuations 8) produces recorded fringes with low accuracy, which results in the distortion of the recorded image. 9,10) We previously reported the effects of phase noise on recording characteristics determined by phase compensation with a plane wave. The multiplexing number was increased to 1.5 by suppressing phase fluctuations 11) using a photopolymer recording material.…”

Improved Signal-to-Noise Ratio Using Phase Compensation in Shift- and Angle-Multiplexed Holographic Data Storage

“…1,2) In particular, the phase and amplitude of recordings stored in holographic data systems are greatly affected. 3) We previously reported the influence of phase noise on recording characteristics that use the finite-difference time-domain and fabricated an optical system that uses phase compensation with a plane wave. To suppress phase fluctuations, 4) the multiplexing number was raised to 50%.…”