Development of the technology of contacting ZnSe infrared optical windows using polyethylene films

We present a novel technology intended for contacting ZnSe IR optical windo ws. Thin polyethylene films located between plates made of ZnSe are irradia ted by strong IR radiation produced by a CO2 laser. The IR radiation caused changes in the structure of the polymer, which result in the high adhesion of polymer to the surfaces of ZnSe elements to be contacted. The technolog y enables contacting that maintains transparency in the broad IR band (1 to 25 mum) except for a few narrow absorption bands. Low wave-front distortio n is established by a thorough interferometry study of contacted elements. The contacted ZnSe elements allow 100 W of CO2 laser radiation to pass for 1 h with no drop in transparency. Special tests prove the high thermal stab ility of the bonded elements. The technology is intended for a wide range o f IR optics applications. (C) 2001 Society of Photo-Optical Instrumentation Engineers.