Use of polarization in interferometry after double passage through turbulence

Experimental observations of the coherence enhancement phenomenon are presented and described . We have illuminated an optically rough moving target through turbulence using two coherent point sources and observed the interference of the scattered fields in the region close to the sources (the region of coherence enhancement) with the help of a special interferometric system. Our study shows that the intensity distribution in the region of coherence enhancement depends on the inner scale of turbulence.

show abstract

“…These two figures are in good qualitative agreement with eqs. (5) and (6). It is interesting to note that in Fig.3b As follows from eq.…”

Section: The Coherence Enhancement Effectmentioning

confidence: 99%

<title>Coherence enhancement of light after double passage through a turbulent medium</title>

et al. 1994

View full text Add to dashboard Cite

show abstract

“…A way to defeat that has been shown recently by Bogaturov, et al [3]. The first difficulty is that significant background radiation accompanies the back-reflected signal.…”

Section: Reciprocal Path Imaging Through the Atmosphere With Sparse Amentioning

confidence: 99%

“…3 predicts that imaging can be achieved by using the two pinholes at many locations to enable recording the 2D Fourier modulus of each of the spatial frequencies represented by the pinholes' separation in circular coordinates (p, 0); the quarter wave plates block the background light so that time averaging does not have to be carried out to pull the signal out of the noise. Ref.…”

Section: Reciprocal Path Imaging Through the Atmosphere With Sparse Amentioning

confidence: 99%

See 1 more Smart Citation

<title>Overview of CREOL programs in laser radar</title>

Stickley

1993

SPIE Proceedings

View full text Add to dashboard Cite

This paper summarizes progress toward developing coherent ladar technology using arrays of subapertures for coping with target-induced speckle which can reduce the carrier-tonoise ratio for ladar systems. We have selected an optimum receiver design, developed algorithms for determining how to co-phase the IF signals from the different sub-apertures! receivers, and have begun to test these on a two-aperture, coherent I 064nm ladar. Computer simulations of the ladar are being developed including partially-developed speckle effects from the target. Target speckle has been measured from different materials and at two different wavelengths for bench-marking the computer simulations. We have measured and are developing the theory for the time-dependent optical phase shifts observed from a rough, rotating target. The signal enhancement has been calculated that might be expected for a rough target illuminated by a coherent, 1064nm laser. Finally, we have designed and are beginning to implement an experiment to show that imaging through a turbulent medium can be achieved.Personnel contributing to this research or included in this program are Profs.It is well known that scattering from a target's surface and!or atmospheric turbulence will cause breakup of a coherent wavefront into speckles. This process limits a single receiver 08 194-11 72-8193/$6.OO

show abstract

“…A cell of heated water having turbulent refractive index fluctuations along the path of light propagation is one example of such random dynamic phase distortions [3] . Strong phase distortions can also be produced using heated air or a warmed glass plate [4,5] .…”

mentioning

confidence: 99%