Abstract: An adhesive with a refractive index of 2.0 and over is transparent at an infra-red band. A production method of the adhesive and a beam splitter prism set is provided. The beam splitter prism set separates middle and far infra-red beam paths for electro-optical monitoring systems according to wavelengths of the middle and far infra-red beam paths, wherein in the electro-optical monitoring systems the adhesive is used.

Abstract: The present invention relates to rendering electro-optical systems (thermal camera, camera, binoculars, sighting device, etc.) unusable (optical darkening). The inventive optical screening system, which prevents reuse of the electro-optical devices by destructing optical components thereof, essentially comprises at least one optical group consisting of the optical components of the electro-optical system, at least one destructive unit which destructs the optical group, at least one triggering unit which activates the destructive unit, at least one management center which issues a command to the triggering unit to start optical screening.