六区域位相板星冕仪的理论研究

发布时间：2018-10-20 09:39

【摘要】：在探测系外行星的过程中，位相板星冕仪由于其简单的结构，高质量的成像，一直起着重要的作用。本论文在简单介绍几种常见的位相板星冕仪的基础上，然后引入了宽带位相板星冕仪，宽带位相板星冕仪能够提供更加丰富的图形信息，减少成像时间，在研究星冕仪的过程中有着重要的意义。我们创新性地提出了六区域位相板星冕仪(six-region phase mask)。然后，通过理论分析，，我们推导出了一般性六区域位相板星冕仪宽带工作条件的具体表达式，其对于寻找宽带位相板有一定的指导作用。通过验证发现，我们研究组以前提出的正弦位相板星冕仪也满足该条件。论文中，我们以标量衍射理论为基础，经过理论分析和数学计算，利用宽带位相板角向上必须是双周期的，由此通过调整位相板的相位分布、运用位相板自身的特性来增加星冕仪的工作带宽。在这个过程中，我们还成功解释了为什么选择六区域位相板而不是七区域位相板或者五区域位相板。在此工作的基础上，我们进一步研究了六区域位相板星冕仪的一种特例——六平台位相板星冕仪。运用二维快速傅里叶变换，我们发现六平台位相板星冕仪有高质量的消光特性，超高的角分辨本领以及超宽的工作带宽。特别地，在500nm到600nm范围内使恒星光的残余量至少减少到原能量的10-3。作为使用单个位相板的星冕仪，该工作带宽已经达到了国际先进水平。
[Abstract]:Because of its simple structure and high quality imaging, the phase plate corona has been playing an important role in the exploration of exoplanets. On the basis of a brief introduction of several common phase plate coronometers, this paper introduces a wideband phase plate corona instrument, which can provide more abundant graphic information and reduce the imaging time. It is of great significance to study the coronal instrument. We creatively propose a six-region phase plate corona (six-region phase mask). Then, through theoretical analysis, we derive the specific expression of the broad band working conditions of the general six-region phase plate corona, which has a certain guiding role in finding the broad band phase plate. It is found that the previous sinusoidal phase plate coronometers proposed by our research group satisfy this condition. In this paper, based on the scalar diffraction theory, through theoretical analysis and mathematical calculation, the angle upward of the wide-band phase plate must be double-periodic, so the phase distribution of the phase plate can be adjusted by adjusting the phase distribution of the phase plate. The working bandwidth of the coronal instrument is increased by using the characteristics of the phase plate itself. In this process, we also successfully explain why we chose the six-region phase plate over the seven-region phase plate or the five-region phase plate. On the basis of this work, we further study a special case of the six-region phase-plate coronator-the six-platform phase-plate corona. By using two-dimensional fast Fourier transform, we find that the six-platform phase plate coronal instrument has high quality extinction characteristics, super-high angular resolution and ultra-wide operating bandwidth. In particular, the residual amount of stellar light is reduced to at least 10-3 of the original energy in the range of 500nm to 600nm. As a coronal instrument using a single phase plate, the bandwidth has reached the international advanced level.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：P111.3

【共引文献】