Rainbow Research Optics, Inc. carries a wide range of len l products and can quickly address customer requirements for fast lens prototyping. Stock materials are as follows: BK 7 and synthetic fused silica, e calcium fluoride (CaF2), germanium (Ge), magnesium fluoride (MgF2), silicon (Si), zinc selenide (ZnSe), and zinc sulfide (ZnS).  Selecting a suitable optical material is critical to maximizing light transmitting through a lens element.  To select your lens call at 303-371-300 and visit online at www.rainbowoptics.com.