红外与激光工程
紅外與激光工程
홍외여격광공정
INFRARED AND LASER ENGINEERING
2015年
1期
317-320
,共4页
王利国%吴振森%王明军%王万君%张耿
王利國%吳振森%王明軍%王萬君%張耿
왕리국%오진삼%왕명군%왕만군%장경
大气光学%广义惠更斯一菲涅尔原理%二阶矩%强湍流%斜程传输
大氣光學%廣義惠更斯一菲涅爾原理%二階矩%彊湍流%斜程傳輸
대기광학%엄의혜경사일비열이원리%이계구%강단류%사정전수
atmospheric optics%extended Huygens-Fresnel principle%second-order moment%strong turbulence%slant path
激光在强湍流中的传输以及斜程传输问题是随机介质波传播研究中的热点,也是难点。文中尝试建立一个可以在任意湍流环境下通用的激光传输二阶矩演化模型。首先利用广义惠更斯-菲涅尔原理及球面波结构函数的二次近似推导了高斯-谢尔波束在大气湍流中传输时的互相干函数表达式。建立了波束互相干函数的三参数模型,得到了三参数的递进公式。利用三参数迭代法计算了部分相干波束在强湍流中及斜程传输时的等效波束半径及相干长度。计算结果证明了在强湍流中,相比于直接利用广义惠更斯-菲涅尔原理的计算结果,迭代法得到的等效半径较小,而相干长度较大。在斜程路径上,上行与下行传输激光的统计特性是不同的。
激光在彊湍流中的傳輸以及斜程傳輸問題是隨機介質波傳播研究中的熱點,也是難點。文中嘗試建立一箇可以在任意湍流環境下通用的激光傳輸二階矩縯化模型。首先利用廣義惠更斯-菲涅爾原理及毬麵波結構函數的二次近似推導瞭高斯-謝爾波束在大氣湍流中傳輸時的互相榦函數錶達式。建立瞭波束互相榦函數的三參數模型,得到瞭三參數的遞進公式。利用三參數迭代法計算瞭部分相榦波束在彊湍流中及斜程傳輸時的等效波束半徑及相榦長度。計算結果證明瞭在彊湍流中,相比于直接利用廣義惠更斯-菲涅爾原理的計算結果,迭代法得到的等效半徑較小,而相榦長度較大。在斜程路徑上,上行與下行傳輸激光的統計特性是不同的。
격광재강단류중적전수이급사정전수문제시수궤개질파전파연구중적열점,야시난점。문중상시건립일개가이재임의단류배경하통용적격광전수이계구연화모형。수선이용엄의혜경사-비열이원리급구면파결구함수적이차근사추도료고사-사이파속재대기단류중전수시적호상간함수표체식。건립료파속호상간함수적삼삼수모형,득도료삼삼수적체진공식。이용삼삼수질대법계산료부분상간파속재강단류중급사정전수시적등효파속반경급상간장도。계산결과증명료재강단류중,상비우직접이용엄의혜경사-비열이원리적계산결과,질대법득도적등효반경교소,이상간장도교대。재사정로경상,상행여하행전수격광적통계특성시불동적。
The problems of laser beam propagation in strong turbulence and the propagation along a slant path are hot and hard points in the subject of light propagation in random media. A model of the second- order moment of laser beam in any turbulence condition was elected. First the expression of the mutual coherent function was derived by using the extended Huygens- Fresnel principle. The model with three parameters for the second- order moment was created and the recursion formulas for the parameters were derived. The iteration formula of the parameters were used to calculated the effective beam radius and the length of coherence in the strong turbulence and in turbulence along a slant path. Compared with the results obtained by directly using the extended Huygens- Fresnel principle in strong turbulence, the effective beam radius obtained by the iteration formula is smaller and the corresponding coherence length is larger. The iteration method also shows that the characteristics of the uplink and downlink laser beam along a slant path are different.