CAJ | 학술논문

受大气湍流影响，空间光通信系统中接收光至单模光纤耦合效率降低，根据弱湍流理论，推导了Kolmogorov湍流信道情况下准直高斯光束至单模光纤平均耦合效率表达式，仿真了1 km传输距离下不同接收孔径下平均耦合效率与湍流强度的关系，结果表明：当大气折射率结构常数达到10-12时，耦合效率降到0.1以下，且耦合效率随接收孔径增大而降低。采用37单元自适应光学系统(AO)进行补偿实验，对畸变波前进行重构再利用反射变形镜进行修正的方法，对比不同AO状态下波面图质量及远场长曝光成像及质心位置漂移，发现AO进行低阶像差校正后，波面峰-谷值及标准差减小、斯特列尔比(SR)及耦合效率增加，进行高阶校正后情况进一步改善。
수대기단류영향，공간광통신계통중접수광지단모광섬우합효솔강저，근거약단류이론，추도료Kolmogorov단류신도정황하준직고사광속지단모광섬평균우합효솔표체식，방진료1 km전수거리하불동접수공경하평균우합효솔여단류강도적관계，결과표명：당대기절사솔결구상수체도10-12시，우합효솔강도0.1이하，차우합효솔수접수공경증대이강저。채용37단원자괄응광학계통(AO)진행보상실험，대기변파전진행중구재이용반사변형경진행수정적방법，대비불동AO상태하파면도질량급원장장폭광성상급질심위치표이，발현AO진행저계상차교정후，파면봉-곡치급표준차감소、사특렬이비(SR)급우합효솔증가，진행고계교정후정황진일보개선。
The coupling efficiency of received optical power into a single-mode fiber is degraded by atmospheric turbulence in a free space optical communication system. The expression of average coupling efficiency of a collimated Gaussian beam into a single-mode fiber was derived under Kolmogorov turbulence channel, according to the theory of weak turbulence statistics. The relations between average coupling efficiency and turbulence intensity under different received aperture in 1 km propagation path were also simulated. The results show that coupling efficiency decreases below 0.1 when refractive-index structure constant rises to 10-12, and coupling efficiency degrades when the received aperture increases. A 37-element adaptive optics system with H-S wavefront sensor was adopted to compensate the efficiency. Compared with long exposure imaging and centroid position offset in different status of AO system, it was found that the P-V value and standard deviation decreased, Strehl ratio and coupling efficiency increased in low-order aberration correction. And things became better when high-order aberration was corrected.