Markov speckle for efficient random bit generation

作者:Horstmeyer Roarke*; Chen Richard Y; Judkewitz Benjamin; Yang Changhuei
来源:Optics Express, 2012, 20(24): 26394-26410.
DOI:10.1364/OE.20.026394

摘要

Optical speckle is commonly observed in measurements using coherent radiation. While lacking experimental validation, previous work has often assumed that speckle's random spatial pattern follows a Markov process. Here, we present a derivation and experimental confirmation of conditions under which this assumption holds true. We demonstrate that a detected speckle field can be designed to obey the first-order Markov property by using a Cauchy attenuation mask to modulate scattered light. Creating Markov speckle enables the development of more accurate and efficient image post-processing algorithms, with applications including improved de-noising, segmentation and super-resolution. To show its versatility, we use the Cauchy mask to maximize the entropy of a detected speckle field with fixed average speckle size, allowing cryptographic applications to extract a maximum number of useful random bits from speckle images.

  • 出版日期2012-11-19