Static laser speckle suppression using liquid light guides

Abstract

Static laser speckle suppression using multimode fibers has practical limitations as the technique requires an extremely long fiber to achieve an acceptable speckle contrast. An effective method based on liquid light guides was developed in this study to suppress laser speckle. In this study, a speckle simulation model of the liquid light guide was established for numerically calculating the speckle contrast without solving the analytical solution of the photon diffusion equation. The obtained simulation results were compared with the experimental results for the dependence of speckle contrast on the required length and numerical aperture with different liquid core types of liquid light guides. A speckle contrast of 12% and a speckle suppression efficiency of 5 was achieved at the end of a 2.4 m long liquid light guide. For the same fiber length, liquid light guides were found to suppress speckle more efficiently when compared to multimode fibers.

Comparison of contrast-to-noise ratios of different detection methods in ultrasound optical tomography

“…been used with the spectral hole burning [ 11 ], speckle contrast [ 19 ], photorefractive [ 28 ] methods. However, light guides partially suppress laser speckle contrast [ 53 ], which would have to be considered for speckle methods.…”

Laser speckle reduction using polymer-stabilized liquid crystals doped with Ag nanowires

“…With the development of laser technology, laser sources have been widely used in projection displays [ [1] , [2] , [3] ]. This is because of the advantages of lasers with high brightness, wide color gamut, low energy consumption, long lifetime, and small size [ 4 ]. However, the high coherence of the laser beam leads to different optical path differences when it irradiates rough surfaces, which causes interference of the scattered light waves in space and in turn generates bright and dark granular spots, called speckles [ 5 ].…”