An 810-nm Narrowband Filter Film for Iris Recognition System

The key to iris recognition is the collection of iris images, and the iris will generate noise during imaging under visible light, which has a serious impact on the performance of the iris recognition system. In order to improve the accuracy of iris recognition, infrared light sources have been widely used in recent years. The iris image acquisition system, this article mainly researches the 810 nm narrowband filter used in this system and the design of the film system. Since narrow-band filters have multiple parameters and design requirements, in order to explore the effects of various parameters on performance, the pass-band width, pass-band rectangularity and steepness in the narrow-band filter plan are simulated based on Essential Macleod software. Based on this experiment, the film system was planned and optimized using the theory of thin film optics. The problems in the actual process of film system design are summarized and discussed. After calculation, the film system designed in this paper has a transmittance of over 98% for the infrared light of 810± 10nm, and a transmittance of less than 0.1% for the visible light range. It can realize the technological requirements of the existing iris recognition system, and has certain value for the application of the iris recognition system.