This paper introduces the infrared optical system in the Tokamak fusion reaction device. In this optical system,
the traditional optical structure can't meet the requirements, because the length of the infrared optical system
in the Tokamak is very long. The design of optical system in the detection facility includes three parts:1.the
combination of the concave aspheric mirror and flat mirror; 2.the Cassegrain system; 3.the relay group lenses.
This paper describes the decrease of the modulation transfer function (MTF) when the temperature changes
and how to compensate the decrease of the MTF in order to maintain the image quality in a high level. As a
result, the image quality of this optical system can reach the requirements when the temperature changes.
Based on reflective liquid crystal spatial light modulator (SLM), a new foveated optical imaging system is proposed.
High quality imaging can be realized at any region of interest (ROI) within the field-of-view (FOV) by utilizing the SLM
to correct the aberration of different regions dynamically. A reflective cassegrain optical structure is proposed, which is
designed, optimized and matched with the reflective SLM to construct a more practical foveated imaging system. This
reflective imaging system has a large aperture so that enough light can reach the image plane. It also makes the total
length of the system shorter and therefore more practical. We also simulate and analyze the system. This kind of foveated
optical imaging system can be applied in wide FOV imaging aspects to reduce bandwidth and optics complexity, and to
achieve weight reduction and miniaturization.
Narcissus can have a deleterious effect on image quality for cooled infrared imaging systems. Therefore, analysis of narcissus is important for designing both scanning and staring optics. Narcissus is generally assumed to be negligible in staring IR optical designs because the shading effects can be removed by calibration of the detector array data. However, the calibration usually decreases sensitiveness of the system and Narcissus variation may be noticeable for sensors when the conditions changes as follows: 1. warming and cooling the optical housing, 2. zooming optical elements, 3. movement of lenses for focus. In that case, it will result in shading and other image defects even after calibration. To minimize these effects, narcissus should be assessed and controlled during the design of staring array IR system. We provided a direct and fast method for analyzing the narcissus variation in the presence of software such as LightTools, TracePro and ASAP, and proposed the principles in optical design of staring IR systems to reduce narcissus. A cooled staring IR system with serious narcissus was estimated and reoptimized. Narcissus analysis of this IR system confirmed the efficiency of the analysis method.