The influence of oceanic turbulence on the beam quality parameters of partially coherent Hermite–Gaussian linear array beams

Abstract

Based on the spatial power spectrum of the refractive index of ocean water and the second-order moments, the influence of oceanic turbulence and array beam parameters on the beam quality parameters including the M2-factor and turbulence distance of partially coherent Hermite–Gaussian linear array (PCHGLA) beams is studied in detail. It has been shown that the M2-factor of PCHGLA beams propagating through oceanic turbulence apparently increases with the increasing propagation distance, the M2-factor and relative M2-factor of PCHGLA beams apparently decrease and the turbulence distance of PCHGLA beams increases with the decreasing rate of dissipation of mean-square temperature and the increasing relative strength of temperature and salinity fluctuation and rate of dissipation of turbulent kinetic energy per unit mass of fluid. For the case of PCHGLA beams with larger beam number and relative separation distance and worse coherence degree, the relative M2-factor is smaller and the turbulence distance is larger, implying that influence of oceanic turbulence on the beam quality becomes weaker under this conditions. The results are illustrated by numerical examples.