With the development of technology, research on solar flares has been gradually developed, and the corresponding detection band also involves hard X-ray. Due to the particularity of hard X-ray, the collimator is generally used to observe it. When observing the sun, the load is required to point at the sun accurately. This paper mainly introduces an optical system for precise pointing to the sun of the solar hard X-ray imager. By optimizing the design, the measurement requirements are satisfied. In addition, the design results, system ghost images and measurement accuracy are analyzed and evaluated.
Synthetic aperture lidar is a new ultra-high resolution optical imaging instrument, but its reception field is very narrow which is subject to the "antenna theory". In this paper, the antenna efficiency theory is used to explain the antenna theory and the method of enlarging the field of view of the synthetic aperture laser radar. Then the increase range of the field angle of the three methods is deduced by heterodyne efficiency simulation. The simulation results show that the focal plane heterodyne detection optical path of the wide-beam local oscillator beam focal plane has the ability to improve the heterodyne efficiency of the edge field of view by reducing the heterodyne efficiency of the central field of view. The focal plane heterodyne detection optical path of the array detector requires the detector whose pixel size less than 3 times Airy spot radius covers the whole field of view, which can increase the maximum 1.83N times compared to the antenna theory. The effective field of the pupil plane heterodyne detection optical path of the array detector has nothing to do with the magnification of the telescope, the pupil diameter, the size of the detector, etc., which can be increased by N times as compared with the antenna theory.
The thermal stability of optical antennas is a key parameter determining the performance of satellite optical communication links. The effects of uniform temperature changes on the performance of a Cassegrain optical antenna are discussed. In addition, a simple theoretical model is proposed to describe the defocusing distance and wavefront aberration (power) as a function of temperature. Through the theoretical model, the thermal stability can be quickly assessed in the optical design stage. The alignment data and thermal experimental results are consistent with the theoretical model.
The use of line-plane-switching infrared fiber bundle to achieve wide field of view push-broom infrared imaging has been studied with experiment. In this technology, the linear array end of the imaging fiber bundle is used as a long-linear array infrared detector, and the plane array end of the bundle is coupled by a mature small scale Infrared Focal Plane Array (IRFPA). It can evade the difficulty of getting the long-linear array infrared detector directly, and has a signally significance to the development of internal infrared imaging technology. Based on the introduction of the composition, working principle of this novel infrared optical system, the system principle-demonstrating experiment has been accomplished. The line-plane-switching fiber bundle used in this experiment is 64×9 format plane array and 192×3 format linear array. It is made from chalcogenide glass fibers, possessing core (As40S59.5Se0.5) of 45 μm, cladding (As40S60) of 5 μm, and error of 1% in diameter. Perfect imaging results prove that this novel technology is feasibility and superiority. The analysis of the experiment makes a foundation for the subsequent further verification experiments.
A new subminiature endoscope which used for reconnaissance and diagnosis has been designed. This subminiature endoscope is designed based on imaging fiber bundle and consist of the front object lens whose aperture is only 0.5mm, imaging fiber bundle and the post coupling lens. It realized by using subminiature optical systems . The FOV(field of view) and the focal length of the front object lens are 50° and 0.59mm. And the object distance, F number and detected imaging high of the front object lens are 3mm, 6 and 0.5mm. The total number of the imaging fiber bundle are 10000 and it’s pixel cell size is 5 μm. The effective aperture of the imaging fiber bundle is 0.46mm. The post coupling lens has a reduction ratio of 1.73. It’s object distance and imaging height are 5mm and 0.8mm. The Numerical Aperture (NA) of the front object lens, imaging fiber bundle and the post coupling lens are matching will. The coupling efficiency of the imaging fiber bundle is above 93% and the system’s design result can meet the need of the limit resolution of the imaging fiber. This kind of the fiber endoscope has the peculiarity of wide FOV, fine imaging quality, compact configuration, low finished cost and etc. It is meaningful to realize the objective of miniaturization, batch-type production and high imaging quality of the endoscope.
Relay lens is an important element for infrared system coupled with imaging fiber bundle. According to the basic composition and structural characteristics of infrared system coupled with imaging fiber bundle, this paper put forward the general principle and method of its relay lens design, then a material relay lens has been designed by ZEMAX with definite performance index. It has a working spectral coverage from 3.7μm to 4.8μm, focal length of 33.5mm, magnification of -0.6, linear field of view of 12mm, objective numerical aperture of 0.15. It is objective telecentric and is adapted to the relay of infrared detector and imaging fiber bundle. The total lens has two aspheric surfaces and only four pieces of singlet. Its MTF value is 0.7@17 lp/mm, and distortion is -0.19%. After necessary tolerance analysis and structural design, this relay lens has been fabricated. The optical performances fulfill the design requirements and clear images have been got by this lens. These prove the validity and rationality of the design method. It gives a foundational guidance for such relay lens design.