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scopeguy20 said:Hey I was an optician in the 80's and we made IR lenses mostly (at Exotic Materials) . The truth is Germanium when totally pure is not perfectly transparent to IR, it needs a "dopant' a very small amount of actinium or arsenic is added in order to get the 99% or so transparency (only once coated for IR anti-reflection) the coatings were also interesting, one kind used multi-layers of elements including thorium. I ran a "Hard Carbon Coating machine, which used plasma and cyclohexane, (a carbon source), to make thin layer man made diamond on the germanium so a wiper with sand after 500 revolutions would not mark, scratch or remove the diamond coat which looked like a very shinny black shoe polish surface. With Hard Carbon the lens or window of doped germanium would pass 99.5% of the IR from 900 to 1600nm these were used on the Apache helicopters' Pilot Night Vision System, (PNVS) and the Tactical Acquisition and Deployment System (TADS) ( Guided Missile system) on the outer most optical surfaces.
the cesium to cool id love to have some of thatheruursciences said:The crystal he was holding in the tellurium video is a Cadmium Telluride OPO element.
Btw Oh check out the Cesium video... I got a vial of it TWICE that size, a quarter kilogram of it.