蒙特卡洛法仿真激光在水下信道中的传输特性

Monte Carlo Simulation on Laser Transmission Characteristics in an Underwater Channel

针对海洋港湾海水强吸收和高散射的特性,文章利用蒙特卡洛方法仿真研究了激光在浑浊港湾海水中的传输特性。文章在一定的光波长、光能量和发散角下,量化分析了水质参数和传输距离对激光的功率、脉冲响应以及光斑质量的影响。研究结果表明,激光在浑浊港湾海水中传输时,随着衰减长度的增加,光功率的衰减特性保持一致,且光功率的衰减速度不符合比尔定律所描述的线性关系。在相同的水质条件下,光脉冲的宽度和光斑的尺寸随着传输距离的增加而增大,但是当传输距离从20个衰减长度传输至30个衰减长度时,光脉冲宽度基本不变,光脉冲展宽量的变化小于1 ns,此时光斑尺寸持续增大。另外,在相同的衰减长度处,光脉冲和光斑的展宽量随着水质衰减系数的增大而减小。

The transmission characteristics of laser in four types of harbor water were studied using Monte Carlo method simulations for the characteristics of strong absorption and high scattering of water in marine harbors.The effects of water quality parameters and transmission distance on the optical signal power,impulse response and spot quality were quantified and analyzed at certain optical wavelengths,optical energies and divergence angles.The analysis shows that the attenuation characteristics of laser remain consistent as the attenuation length increases when the optical signal is transmitted in the four types of harbor waters.The rate of attenuation of the optical power also does not conform to the linear relationship described by Beer's law.Under the same water quality conditions,the width of the optical pulse,the size of the light spot increases with the attenuation length.However,when the attenuation length is transmitted from 20 to 30,the width of the optical pulse is almost unchanged,and the change in the amount of light pulse spreading is less than 1 ns with the size of the light spot increases continuously.In addition,at the same attenuation length,the light pulse and the spreading amount of light spot with the water quality attenuation coefficient increases and decreases.