Optical phase and amplitude measurements of underwater turbulence via self-heterodyne detection

被引：2

作者：

Ferlic, Nathaniel a. ^{[1
]}

Laux, Alan e. ^{[1
]}

Mullen, Linda j. ^{[1
]}

机构：

[1] Naval Air Warfare Ctr Aircraft Div, 22347 Cedar Point Rd, Patuxent River, MD 20670 USA

来源：

JOURNAL OF THE OPTICAL SOCIETY OF AMERICA A-OPTICS IMAGE SCIENCE AND VISION | 2024年 / 41卷 / 06期

关键词：

TEMPERATURE-FLUCTUATIONS; THERMAL-CONVECTION; NON-KOLMOGOROV; SPECTRUM; NUMBER; LIGHT; DISSIPATION; PROPAGATION; INTENSITY;

D O I：

10.1364/JOSAA.520917

中图分类号：

O43 [光学];

学科分类号：

070207 ; 0803 ;

摘要：

The creation of underwater optical turbulence is driven by density variations that lead to small changes in the water's refractive index, which induce optical path length differences that affect light propagation. Measuring a laser beam's optical phase after traversing these turbulent variations can provide insight into how the water's turbulence behaves. The sensing technique to measure turbulent fluctuations is a self-heterodyne beatnote enhanced by light's orbital angular momentum (OAM) to obtain simultaneous optical phase and amplitude information. Experimental results of this method are obtained in a water tank that creates a thermally driven flow called Rayleigh-B & eacute;nard (RB) convection. The results show time-varying statistics of the beatnote that depend on the incident OAM mode order and the strength of the temperature gradient. Beatnote amplitude and phase power spectral densities are compared to analytic theory to obtain estimates of the turbulent length scales using the Taylor hypothesis that include mean flow speed, turbulent strength, and length scales, and flow dynamics due to intermittency in the RB process. (c) 2024 Optica Publishing Group

引用

页码：B95 / B105

页数：11