Design of optical thin film systems for ultraviolet narrow-band interference filters based on needle optimization technique

Abstract

Solar blind ultraviolet communication systems can provide short to medium range non line-of-sight and line-of-sight links which are covert and insensitive to meteorological conditions. These unique properties endow solar blind ultraviolet communication systems increasing applications. While optical filters are key components of these solar blind ultraviolet communication systems. Although filters can be designed in different forms, thin-film interference narrowband filters are widely adopted. In this paper, we make use of NCNBIF, which was so-called nonconventional narrowband interference filters proposed by Jerzy Ciosek firstly, to design ultraviolet narrow-band interference filters. Generally, classical narrow-band interference dielectric filters, such as Fabry-Pérot filters, have a half-wave-thickness spacer layer. In contrast with a classical interference filter, the NCNBIF does not have a half-wave-thickness spacer layer. This spacer layer of NCNBIF consists of two different materials. This new kind of film system (NCNBIF) is synthesized by using needle optimization technique, and possesses desired spectral characteristics.