# Evolution properties of coherent Gaussian vortex beams propagating through weak oceanic turbulence and its application for measurement

## TL;DR

This paper analyzes how coherent Gaussian vortex beams evolve when passing through weak oceanic turbulence, revealing their potential for sensitive, non-contact measurement of turbulence strength via optical tomography.

## Contribution

It derives the cross-spectral density of such beams using extended Huygens-Fresnel principle and explores their evolution, highlighting their application in oceanic turbulence measurement.

## Key findings

- Non-zero separation enhances turbulence effects on interference.
- Intensity variation relates to turbulence strength and beam parameters.
- High sensitivity to turbulence enables potential optical tomography applications.

## Abstract

The cross-spectral density of coherent Gaussian vortex beams propagating through weak oceanic turbulence is derived from extended Huygens-Fresnel principle and Nikishov spectrum. The evolution of a coherent superposition field composed of dual Gaussian vortex beams with $+1$ and $-1$ topological charges respectively through weak oceanic turbulence is investigated in z plane and y plane. It is shown that the non-zero separation distance of two beams in x direction enhances the oceanic turbulence effect on interference light field. The variation of intensity distribution in z plane and on the central axis of two beams in y plane are both related to the strength of oceanic turbulence, separation distance, propagation distance and waist width. The extra fluctuation of the intensity on the central axis of two beams in y plane leads to high sensitivity of oceanic turbulence. This characteristic has potential application in non-contact optical tomography of oceanic turbulence strength along the beam propagation path by lateral scattering intensity.