ABSTRACT
The analytical formula for characteristic parameters of optical wave (wave structure function, spatial coherence radius, and Fried parameter) in the slant path of ocean turbulence are derived and analyzed. Under the Rytov approximation, the wave structure function derived by the oceanic power spectrum of the refractive index of optical turbulent fluctuations in the slant path still complies with the five-thirds power law of the Kolmogorov spectrum in the inertial subregion, and the relationship between spatial coherence radius and Fried parameters satisfies 2.1 times. The correctness of analytical formulation of the wave structure function is demonstrated by comparing the numerical results of the original integral formula with the analytical formula of the derived in this paper.
ABSTRACT
Maksutov-Cassegrains are widely used in free-space optical communication. The coupling efficiency and variance of a Maksutov-Cassegrain fiber (single-mode) system distorted by atmospheric turbulence are numerically evaluated using second-order and fourth-order moments under a Von Karman spectrum. Considering the limited cost and size of the equipment, the Maksutov-Cassegrain aperture should satisfy DA/ρS≈7 (ρS approximates the characteristic atmospheric coherence length), and the obscuration ratio should be no more than 0.2.
