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Correlation-enhanced control of wave focusing in disordered media (Conference Presentation)
Author(s): A. Douglas Stone; Chiawei Hsu; Seng-Fatt Liew; Arthur Goetschy; Hui Cao

Paper Abstract

Focusing of light within and beyond a strong scattering disordered medium via wavefront shaping (WFS) using a spatial light modulator (SLM) has been demonstrated for speckle-sized target regions over a decade ago, and has since been explored extensively with potential applications for imaging, phototherapy, communications and cryptography. The intensity enhancement scales linearly with the number, M1, of SLM pixels and is unaffected by any correlations in the speckle field of transmitted or reflected light. However, a fundamental question of great importance for applications is the possibility of focusing to regions much larger than a single speckle, where neglect of correlations would predict a decrease in the enhancement as 1/M2, where M2 is the number of speckles in the target region. It has been known for many years that speckle patterns from highly scattering media have long-range field correlations. We have developed a quantitative theory of the effect of these correlations on large scale focusing and demonstrated excellent agreement between the theory and experiments on the transmission of light through ZnO nanoparticles. The correlations between speckles allows much greater control via WFS of focusing to larger target regions than the simple prediction above. Specifically, for a given sample, each set of experimental illumination conditions defines a measurable dimensionless number, g, which controls focusing efficiency. When the dimensionless size of the target region, M2 > g, significantly enhanced focusing through WFS is possible due to correlations, with the maximal enhancement increasing by M2/g compared to the result in the absence of correlations.

Paper Details

Date Published: 15 March 2018
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Proc. SPIE 10502, Adaptive Optics and Wavefront Control for Biological Systems IV, 105020T (15 March 2018); doi: 10.1117/12.2293693
Show Author Affiliations
A. Douglas Stone, Yale Univ. (United States)
Chiawei Hsu, Yale Univ. (United States)
Seng-Fatt Liew, Yale Univ. (United States)
Arthur Goetschy, Institut Langevin (France)
Ecole Supérieure de Physique et de Chimie Industrielles de la Ville de Paris (France)
Hui Cao, Yale Univ. (United States)


Published in SPIE Proceedings Vol. 10502:
Adaptive Optics and Wavefront Control for Biological Systems IV
Thomas G. Bifano; Joel Kubby; Sylvain Gigan, Editor(s)

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