Multispectral Silicon Beam-Splitter for VNIR, SWIR and MWIR

Abstract

Abstract Multispectral electro-optical/infrared payloads are being developed for a variety of defence and commercial system applications. Many applications depend on its ability to detect and recognize low-contrast and distant targets in a complex environment. The development of such systems necessitates the use of specialized optical filters capable of separating different spectral bands. We have designed and developed silicon-based plate beam splitter for 45-degree angle of incidence that will be used to separate the bands from visible to MWIR. This beam-splitter separates MWIR from VNIR and SWIR. The silicon beam splitter was developed using an ion-assisted e-beam evaporation technique. An average reflection of ~ 75% in visible and ~ 83% in SWIR region was measured using double beam spectrometer 1050 from M/s Perkin Elmer. An average transmission ~ 85% in the MWIR region was measured using FTIR frontier spectrometer from M/s Perkin Elmer.