Improvement of young's fringes' visibility in speckle photography by use of BSO-PROM device

<title>Real-time speckle photography using photorefractive Bi12SiO20 crystal</title>

“…The intensity correlation function between two speckle patterns Ia(x) and Ib(i) on the specklegram can be considered that (3-a) <Ib(xi)Ib()>/<I>2= 1+ exp[-f r/r.I 2], (3-b) where rx2x1, r is the average radius of speckles recorded on the specklegram, A the speckle displacements between two exposure patterns, and ' the decorrelation factor between two speckle patterns caused by the boiling of speckles5 and/or the difference of the exposure conditions. (4) where E0 is the amplitude of its electric field, io the center position, and W the beam radius, Using the aptude transmission T(x) of the specklegram, the impulse response function K(x, ) of the optical system and E0(), the electric field EU ) of the light on the observation plane is written as -. E(E)= I E0()T() K(",) d'.…”

“…(2) In the proposed real time speckle photography, BSO crystal was used in PR (Photorefractive) type device23 or PROM (Pockels Readout Optical Modulator) device. 4 Both the structure and the operating condition are dii'-ferent in these two kinds of device. The recording mechanisms of the specklegram and the structure of Young fringes from these devices are also different.…”

Optical processing by fringed speckles registered in a BSO crystal

“…In particular, Leith and Upatnieks 1 used different spatial carriers by employing a diffuser for different spatial signals. [5][6][7][8][9][10] The use of BSO crystals for recording and processing double-exposure speckle patterns has been demonstrated experimentally; 5,6 they are used instead of photographic plates, in conventional arrangements, for real-time and in situ measurement of displacements. Also, the angular selectivity of volume holograms has been exploited to increase the multiplexing capability.…”