Propagation of a Lorentz Non-Uniformly Correlated Beam in a Turbulent Ocean

Abstract

We study the propagation characteristics (spectral intensity and degree of coherence) of a new type of Lorentz non-uniformly correlated (LNUC) beam based on the extended Huygens–Fresnel principle and the spatial power spectrum of oceanic turbulence. The effects of the oceanic turbulence parameters and initial beam parameters on the evolution propagation characteristics of LNUC beams are studied in detail by numerical simulation. The results indicate that such beams exhibit self-focusing propagation features in both free space and oceanic turbulence. Decreasing the dissipation rate of kinetic energy per unit mass of fluid and the Kolmogorov inner scale, or increasing the relative strength of temperature to salinity undulations and the dissipation rate of mean-square temperature of the turbulent ocean tends to increase the negative effects on the beams. Furthermore, we propose a strategy of increasing the beam width and decreasing the coherence length, to reduce the negative effects of the turbulence.

Radially Phased-Locked Hermite–Gaussian Correlated Beam Array and Its Properties in Oceanic Turbulence

“…The CSD of PCBs propagating in oceanic turbulence is described by the extended Huygens-Fresnel principle [9][10][11][12][13][14][15][16][17][18][19]:…”

“…The parameters in Equation ( 6) are A T = 1.863 × 10 −2 , A S = 1.9 × 10 −4 , A TS = 9.41 × 10 −3 , Θ = 8.284(κη) 4/3 + 12.978(κη) 2 . The T 0 can be given as [12]:…”

“…Based on the derived equations, the average intensity of an RPLHGSM beam array in oceanic turbulence is written as [9][10][11][12][13][14][15][16][17][18][19]:…”

“…The self-splitting structured beam can lower the negative influences of oceanic turbulence, which is achieved by controlling the parameters of the beams [10]. The influences of oceanic turbulence on non-uniformly correlated beams have been studied by numerical simulation [11,12]. The propagation of vortex beams in oceanic turbulence has been investigated, and neural networks have also been used in studies of vortex beams in underwater turbulence [13][14][15][16][17].…”

Properties of a Lorentz correlated beam in uniaxial crystal

“…21 Recently, the Lorentzcorrelated Schell-model (LCSM) beam with the cusped shape is introduced, 6 and the LCSMB is also extended to nonuniform LCSMB. 22 However, the effects of uniaxial crystal on LCSMB are not investigated. In this work, the analytical expressions of an LCSMB through uniaxial crystal orthogonal to the optical axis are derived, and the intensity distribution and degree of coherence (DOC) of an LCSMB are investigated.…”