Photometric stability of multiconjugate adaptive optics
Photometric stability of multiconjugate adaptive optics
复制标题
多共轭自适应光学器件的光度稳定性
DOI：
--
复制
发表时间：
2004
期刊：
影响因子：
--
通讯作者：
O. Lühe
中科院分区：
文献类型：
--
作者：
O. Lühe
我们观察到，一个多共轭自适应光学（MCAO）系统产生快速波动的辐照度的几个百分点，在补偿焦平面时，观察一个扩展的目标，如太阳表面。这种波动在未补偿的焦平面中是不存在的。这种起伏与变形镜在与高空湍流层共轭的平面内的局部曲率有明显的关系。它们可以用高空湍流层引入的有效焦距的场相关变化来解释，这与图像失真有关。使用一个简单的几何模型的MCAO系统，我们能够重现所观察到的辐照度的影响。我们建议在标称出瞳的位置处引入稍微过小的孔径光阑，以去除补偿场中的波动。
We observe that a multi-conjugate adaptive optics (MCAO) system produces rapid fluctuations of irradiance of a few percent in the compensated focal plane when observing an extended target, such as the solar surface. Such fluctuations are absent in the uncompensated focal plane. The fluctuations are apparently correlated with the local curvature of deformable mirror in the plane conjugated to the high altitude turbulence layer. They can be explained by the field dependent change of effective focal length introduced by a high altitude turbulence layer, which is related to image distortion. Using a simple geometric model of the MCAO system, we are able to reproduce the observed irradiance effects. We propose to introduce a slightly undersized aperture stop at the location of the nominal exit pupil in order to remove the fluctuations in the compensated field.