Modeling and analysis for the mirror tilt angle error of the image mapper

The snapshot image mapping spectrometer (IMS) is the development of modern optical imaging instruments that combine advanced technologies in medical, biomedicine, remote sensing, etc. The technology has the potential of becoming a fundamental research for high-resolution and high-throughput optical imaging system. The image mapper is the most critical component in the IMS technology and consists of many mirror facets fabricated with a 2D tilt angle. However, these components are very difficult to fabricate and often become the limiting factor in the performance of the system. Therefore, the mirror 2D tilt angle errors are presented for analyzing the center of pupils to be displaced in the virtual apertures in the system. In this research, to accurately describe the relation between reflected light's steering angle and corresponding mirror facet's tilt angle. We propose a light ray tracing model which provides a rigorous analytical solution for the relation between mirror facet's tilt angle and reflected light's steering angle. Then the mirror tilt angle error model was established to analyze the influence of the image mapper based on reflected light's steering angle. The results indicate that the tilt angle error increased causes the deviation from the center of the sub aperture, decrease the image intensity and loss of light throughput. The proposed method can be used to estimate the accuracy of sub pupil's center position, and the conclusions will be helpful in the design and manufacture of the image mapper.