Broadband High-reflective Omnidirectional Mixed-quasi-periodic Multilayer

In this paper, we proposed an omnidirectional reflector of Fibonacci and periodic mixed-multilayer based on the flexible features of quasi-periodic sequences. We combined the Fibonacci sequence and periodic sequence to form a broadband high reflective omnidirectional multilayer system. When light is incident normally, high reflectivity above 99.9% can be achieved over the visible region from 407 nm to 840 nm, much wider than that of traditional periodic multilayer of equal layer number. For the incident range above 40°, although some defects appear in the high reflectance band, a broad reflectance band (R>99%) has remained. This scheme of cascade Fibonacci and periodic mixed-multilayer film can be extended from optical to near-infrared fields, which should have significant prospects for future design of omnidirectional reflectors.