摘要
研究了在非科尔莫哥罗夫湍流下,超连续谱光源的水平传输特性。将超连续谱视为多个窄带光谱分量的叠加。利用互谱密度方法,考虑大气衰减的影响,计算了在不同的湍流内外尺度下,光源的束宽和传输效率随非科尔莫哥罗夫谱α参数的变化关系;以及在不同湍流强度下,束宽和传输效率随光束质量的变化关系。分析结果表明:α参数和湍流的内外尺度会对超连续谱光源的传输特性产生影响。湍流会影响光束束宽,并降低光传输效率;当超连续谱光源的光谱分量为高斯基模时,湍流对其传输特性的影响尤为强烈;而当光谱分量为高阶模时,湍流带来的影响变弱,衍射成为影响传输效率的主要因素。
The horizontal propagation characteristics of supercontinuum source in non-Kolmogorov turbulence is investigated. A superposition of narrow-band spectral components is used to simulate supercontinuum. The beam width of supercontinuum source and propagation efficiency are calculated with different inner and outer scales of turbulence and parameters a, as well as with various turbulence levels and different beam qualities for the spectral parts of supercontinuum source. The method of cross-spectral density is introduced here, and the atmospheric extinction is considered. It is shown that the change of parameter a, the outer scale and inner scale of turbulence, bring about different numerical results. It is also shown that turbulence can influence the beam width and induce deterioration of propagation efficiency, especially for the situation that all the spectral parts of supercontinuum source are Gaussian fundamental modes. When the spectral parts are higher-order modes, the factor affecting propagation of supercontinuum source dominantly is diffraction.
出处
《中国激光》
EI
CAS
CSCD
北大核心
2014年第4期232-238,共7页
Chinese Journal of Lasers
关键词
大气光学
非科尔莫哥罗夫湍流
超连续谱光源
互谱密度
传输特性
atmospheric optics
non-Kolmogorov turbulence
supercontinuum source
cross-spectral density
propagation characteristics
