Athermalization of a Type of Fisheye Optical System in the Temperature Range of Iran
Authors
Abstract
The fisheye system belongs to the family of ultra-wide field of view lenses and has various applications in science, industry, surveillance and artistic fields. Such lenses can cover a field of view of 180 degrees or even larger in the shape of a hemisphere, and therefore can provide the possibility of imaging a large part of the surrounding space with just one shot. Due to the wide temperature changes in Iran, the optical performance of this system is significantly reduced under the influence of the change in the radius and thickness of the surfaces and the change in the refractive index of its glasses. Therefore, in order to achieve optical-thermal stability in the temperature range of Iran, it is necessary to athermalize the system so that temperature changes do not cause a noticeable decrease in the optical performance of the system. In this work, a type of fisheye optical system is redesigned in the visible light spectrum bandwidth and then it is athermalized in the temperature range of Iran from -46 to 70 degrees Celsius.