基于自适应光学技术的太阳光栅光谱仪的像差校正方法研究

Study on the Aberration Correction Method of Solar Grating Spectrometer Based on Adaptive Optics

太阳光栅光谱仪是研究太阳大气分层结构特性的重要仪器,其性能受到大气扰动及系统装配误差等引入的波前像差的限制,需要采用自适应光学进行校正。由于光栅光谱仪中的狭缝对波前像差的滤波作用,使得传统自适应光学无法直接用于光栅光谱仪中。研究了狭缝对自适应光学技术波前校正能力的影响,提出了一种基于狭缝滤波灵敏度的差别校正方法并进行了数值模拟仿真分析。数值仿真结果表明:自适应光学校正后,由像差引起的光谱分辨率衰减量总体上优于1%,从而说明了该校正方法能有效地抑制大气扰动和系统静态像差所引起的光谱展宽,从而提高了光谱分辨率。自适应光学校正后能够有效地提高能量利用率η,当狭缝宽度为3倍艾里斑直径时,η由校正前的约20%提高到了90%以上。

Grating spectrometer is one of important tool to study the thermodynamics properties of the solar atmosphere with different height distributions, but its imaging performance will be limited by the wavefront aberration generated by atmospheric turbulence and optical system adjusting errors and so on, so daptive optics （AO） is needed to compensate the influence of the wavefront aberration. However, the traditional adaptive optics can not be directly applied in the grating spectrometer, since the tiny slit will filter the wavefront aberration to a certain extent. The influence of filter slit on the adaptive optics correction is studied. A differential correction method based on the sensitivity of the filter slit is proposed and the numerical simulation is conducted. The results show that after the adaptive optics correction, the spectral resolution is notably improved, and also the energy utilization 77 is considerably improved, better than 9096 with a slit width of 3 times diameter of Airy spot.