Observation window and application thereof

The invention relates to a viewing window and to the use of a viewing window, comprising a plate-shaped glass substrate and a coating arranged on at least one surface of the substrate, the viewing window having an average transmittance [tau] avg of less than 15%, preferably less than 10%, in the wavelength range of 400 to 700 nm, 400 nm to 700 nm, the [tau] avg, preferably less than 10%, in the wavelength range of 400 to 700 nm, 400 nm to 700 nm is defined as # imgabs0 # and/or the viewing window has a spectral transmittance at each wavelength of less than 15%, preferably less than 10%, particularly preferably less than 5%, very particularly preferably less than 1%, and wherein the transmittance of the viewing window is at least 75%, preferably at least 80%, at at least one wavelength in the wavelength range of 875 nm to 1600 nm. 本发明涉及一种观察窗以及观察窗的应用，该观察窗包括板状的玻璃基底和布置在基底的至少一个表面上的涂层，其中，在400至700nm的波长范围中，所述观察窗具有低于15％、优选低于10％的平均透射率τavg,400nm-700nm，其中，τavg,400nm-700nm定义为#imgabs0#和/或所述观察窗在每种波长的情况下具有小于15％、优选小于10％、特别优选小