Statistical properties of a laser pointer speckle field at different propagating distances

Authors

  • Roel Baybayon ⋅ PH Central Mindanao University
  • Lesley Joy T. Baldonado ⋅ PH College of Arts and Sciences, University of Northern Philippines, Vigan City, Ilocos Sur 2700, Philippines
  • Marsden I. Badlisan ⋅ PH National Institute of Physics, University of the Philippines Diliman, Quezon City, 1101 Philippines
  • Nathaniel P. Hermosa ⋅ PH National Institute of Physics, University of the Philippines Diliman, Quezon City, 1101 Philippines

Abstract

In this paper, we analyze the intensity distribution of the speckle pattern, its average size, and the optical memory effect at different propagating distances, z, when we scatter a light source with low spatial coherence. We produce the speckle field by illuminating the light source onto a ground glass and capture the speckle images at different propagating distances, z, and with different tilting angles to measure the optical memory effect. The probability density function tells us that the speckle field approaches being fully developed as the propagation distance increases. By tilting the ground glass from 0to 1at a 0.01increment, we note a small increase in the full width at half maximum (FWHM) of the correlation as we increase the z, indicating that the optical memory effect of the speckle is slightly larger at greater distances from the scattering medium compared to regions closer to it. Lastly, we plot the autocorrelation function at different distances, z, and observe an increase in speckle size with increasing propagation distance as expected. Our results reveal a fundamental property of speckle, which will be significantly important for numerous applications, such as image reconstruction and the measurement of cerebral blood flow and brain function.

Issue

Article ID

SPP-2024-PD-14

Section

Poster Session D (Photonics and Instrumentation Physics)

Published

2024-06-27

How to Cite

[1]
R Baybayon, LJT Baldonado, MI Badlisan, and NP Hermosa, Statistical properties of a laser pointer speckle field at different propagating distances, Proceedings of the Samahang Pisika ng Pilipinas 42, SPP-2024-PD-14 (2024). URL: https://proceedings.spp-online.org/article/view/SPP-2024-PD-14.