强湍流效应下不同信标波长的自适应光学校正

激光在大气中长距离传输时所产生的相位不连续点的数目与位置不仅与大气湍流和传输距离有关，而且与传输的激光波长有关。由于对主激光进行补偿的相位是从畸变的信标光场中获得的，当畸变光场中出现相位不连续点后，畸变光场的相位由连续相位部分和不连续相位部分组成，不连续相位部分直接与畸变光场中出现的相位不连续点的数密度和其所在的位置有关，一般情况下，主激光的波长与信标光的波长是不同的，因此当主激光的波长一定后，为了对不连续相位进行补偿，以便提高强湍流效应条件下的自适应光学校正能力，必须要考虑合作信标的波长。计算结果表明，考虑了不连续相位的影响后，虽然对主激光的校正效果有所改善，但对不同波长的信标改善的效果并不相同，只有信标光波长稍长于主激光的波长时，校正效果才有明显的改善。

Compensation Analysis for Different Beacon Wavelengths in Strong Turbulence with Adaptive Optics

Under certain conditions, light wave propagation through atmospheric turbulence can cause presence of branch points. The number of branch points in the turbulence-distorted optical field is related with the strength of atmospheric turbulence, propagation range and the wavelength of laser propagated. The phase of compensating main laser is acquired from the distorted field of beacon. But the phase of the beacon is composed of the continuous phase and discontinuous phase when there are branch points in distorted field. The discontinuous phase is related to the number and location of branch points in distorted field, and the wavelength of main laser is always different from the wavelength of the beacon. Therefore, when the wavelength of main laser propagated is determined, the wavelength of beacon must be chosen so that the turbulence-compensated power of adaptive optical system can be improved after the branch-point considered in strong scintillation. The calculated results show that the compensation effect of adaptive optical system can be slightly improved when the branch points in turbulence-distorted optical field are considered, but the correction result of adaptive optics can become much better when the beacon wavelength chosen approaches the wavelength of main laser.