Research on ultraviolet detector technology based on optical conversion

The ultraviolet radiation of the missile plume is an important target for the space-based UV warning system, but its intensity is several orders of magnitude weaker than the infrared radiation. Therefore, the detector used to detect the ultraviolet radiation of the missile plume must have the characteristics of high sensitivity and low noise in order to detect weak signals. At present, the imaging detector used in UV detecting systems is mainly vacuum device, which has the advantages of UV sensitivity and high gain, but its quantum efficiency is low, generally 10% - 20%. Meanwhile, due to the vacuum and high voltage working conditions,the device is easy to be affected by space radiation and the service life of the device is very short. In addition, for vacuum device ,the spectrum range is narrow, which limits the application field of the detector. At the same time, the current vacuum devices can not work in the strong solar background, and it needs to use the composite filter components with small caliber and large thickness. Consequently, the field of view and the efficiency of the optical system are limited, which seriously affect the performance of the space remote sensor. In this paper, the research of high efficiency UV imaging detector based on spectral conversion is carried out. The efficient conversion and detection from ultraviolet to visible light can be realized by using the combination of down conversion light materials and large array visible light charge couple device (CCD) through special technology.Firstly, in order to meet the requirements of optical conversion materials and coupling technology, the composition and system selection of photon conversion nanomaterials are completed by using the theory of rare earth spectrum. Secondly, the coupling process design is carried out, and the advantages and disadvantages of spin coating and thermal evaporation are verified by experiments. The coupling between materials and devices is realized, and the quantitative measurement method of quantum efficiency is given. On this basis, the down conversion UV camera is developed to verify the in orbit technology, and the in orbit image is obtained, which proves the feasibility and effectiveness of the down conversion UV detector technology.