Yousefi Masoud, Golmohammady Shole, Mashal Ahmad, Kashani Fatemeh Dabbagh
J Opt Soc Am A Opt Image Sci Vis. 2015 Nov 1;32(11):1982-92. doi: 10.1364/JOSAA.32.001982.
In this paper, on the basis of the extended Huygens-Fresnel principle, a semianalytical expression for describing on-axis scintillation index of a partially coherent flat-topped (PCFT) laser beam of weak to moderate oceanic turbulence is derived; consequently, by using the log-normal intensity probability density function, the bit error rate (BER) is evaluated. The effects of source factors (such as wavelength, order of flatness, and beam width) and turbulent ocean parameters (such as Kolmogorov microscale, relative strengths of temperature and salinity fluctuations, rate of dissipation of the mean squared temperature, and rate of dissipation of the turbulent kinetic energy per unit mass of fluid) on propagation behavior of scintillation index, and, hence, on BER, are studied in detail. Results indicate that, in comparison with a Gaussian beam, a PCFT laser beam with a higher order of flatness is found to have lower scintillations. In addition, the scintillation index and BER are most affected when salinity fluctuations in the ocean dominate temperature fluctuations.
在本文中，基于扩展的惠更斯 - 菲涅尔原理，推导了用于描述弱到中等海洋湍流条件下部分相干平顶（PCFT）激光束轴上闪烁指数的半解析表达式；进而，通过使用对数正态强度概率密度函数，评估了误码率（BER）。详细研究了源因素（如波长、平顶阶数和光束宽度）以及海洋湍流参数（如科尔莫戈罗夫微尺度、温度和盐度波动的相对强度、平均平方温度的耗散率以及单位质量流体湍动能的耗散率）对闪烁指数传播行为的影响，从而对误码率的影响。结果表明，与高斯光束相比，具有更高平顶阶数的PCFT激光束具有更低的闪烁。此外，当海洋中的盐度波动主导温度波动时，闪烁指数和误码率受到的影响最大。
