红外与激光工程
紅外與激光工程
홍외여격광공정
INFRARED AND LASER ENGINEERING
2015年
1期
305-309
,共5页
空间相干度%高斯- 谢尔模型%阵列光束%大气湍流%交叉谱密度函数
空間相榦度%高斯- 謝爾模型%陣列光束%大氣湍流%交扠譜密度函數
공간상간도%고사- 사이모형%진렬광속%대기단류%교차보밀도함수
degree of spatial coherence%Gaussian Schell-model%array beams%atmospheric turbulence%cross-spectral density function
基于广义Huygens- Fresnel原理和Rytov相位结构函数二次近似的方法,推导出了径向分布高斯-谢尔模(GSM)阵列光束在湍流大气中传输时的交叉谱密度函数解析表达式,并利用表征光束相干性的空间复相干度系数,详细分析了GSM阵列光束在大气湍流中传输时的空间相干性变化规律。研究结果表明:径向分布GSM阵列光束的空间相干性由子光束空间相干长度、传输距离、大气折射率结构常数及相对径向填充因子等因素共同确定;径向分布GSM阵列光束通过湍流大气时,其空间相干度在传输过程中会出现多峰值现象,但是随着传输距离增大,多峰值现象逐渐消失并趋向于高斯分布,并且随着距离增大空间相干度宽度逐渐减小,光束空间相干性变差。
基于廣義Huygens- Fresnel原理和Rytov相位結構函數二次近似的方法,推導齣瞭徑嚮分佈高斯-謝爾模(GSM)陣列光束在湍流大氣中傳輸時的交扠譜密度函數解析錶達式,併利用錶徵光束相榦性的空間複相榦度繫數,詳細分析瞭GSM陣列光束在大氣湍流中傳輸時的空間相榦性變化規律。研究結果錶明:徑嚮分佈GSM陣列光束的空間相榦性由子光束空間相榦長度、傳輸距離、大氣摺射率結構常數及相對徑嚮填充因子等因素共同確定;徑嚮分佈GSM陣列光束通過湍流大氣時,其空間相榦度在傳輸過程中會齣現多峰值現象,但是隨著傳輸距離增大,多峰值現象逐漸消失併趨嚮于高斯分佈,併且隨著距離增大空間相榦度寬度逐漸減小,光束空間相榦性變差。
기우엄의Huygens- Fresnel원리화Rytov상위결구함수이차근사적방법,추도출료경향분포고사-사이모(GSM)진렬광속재단류대기중전수시적교차보밀도함수해석표체식,병이용표정광속상간성적공간복상간도계수,상세분석료GSM진렬광속재대기단류중전수시적공간상간성변화규률。연구결과표명:경향분포GSM진렬광속적공간상간성유자광속공간상간장도、전수거리、대기절사솔결구상수급상대경향전충인자등인소공동학정;경향분포GSM진렬광속통과단류대기시,기공간상간도재전수과정중회출현다봉치현상,단시수착전수거리증대,다봉치현상축점소실병추향우고사분포,병차수착거리증대공간상간도관도축점감소,광속공간상간성변차。
Based on the extended Huygens-Fresnel principle and the quadratic approximation of Rytov's phase structure function, the analytical expression for the cross-spectral density function of the Gaussian Schell-Model (GSM) array beams propagating in atmospheric turbulence was derived. The degree of spatial coherence of GSM array beams in atmospheric turbulence was investigated numerically. The result shows that the spatial coherence properties of the GSM array beams are determined by the coherent length of beamlets, the transmission distance, the refractive index structure constant of atmospheric turbulence and the relative radial fill factor of the source in common. It also shows that the spatial coherence of the GSM array beams ends as Gaussian distribution, but multiple peaks are existed during the transmission, the width of the degree of coherence becomes smaller with the transmission distance continues increase which means that the degree of spatial coherence turns worse.