Recent advancements in multiband IR sensor windows

Abstract

We have developed several rugged materials for multiband applications in the 0.2-12.0 μm wavelength region. These materials include spinel ceramic and barium gallogermanate (BGG) glass which transmit in the UV, visible, SWIR and MWIR wavelength region. They also include MILTRAN^TM and IR glasses which transmit in the SWIR, MWIR and LWIR. These materials have superior mechanical and optical properties compared to the currently used materials on various Navy / DoD systems. Spinel ceramic is comparable to sapphire in its ruggedness but it overcomes the birefringence and poor 4-5 μm transmission of sapphire. Spinel has also been made into large size windows as well as domes for several applications. BGG glass is very useful for systems requiring very large windows with visible - MWIR transmission. High optical quality BGG glass windows in sizes up to 20" in diameter have been made. MILTRAN^TM is > 3 times harder and stronger than ZnS and can provide a rugged window or dome for broadband sensors. IR glass can be easily made in complex shapes. BGG glass and spinel ceramic laminated dome was developed for tri-mode seeker. MILTRAN^TM and IR glasses can be combined to make achromats for multispectral imaging systems.