The present invention relates to a device for an optical system that comprises objective and detector (reticle) or detector surface(s) interacting with this via a stop aperture.
The object of the present invention is among other things to prevent reflections in the detector or reticle leaving the optical system and making it possible for other parties to detect or discover the equipment or activity concerned. In order to solve this problem, in military connections there has been an attempt to reduce the reflectance of the detector or reticle. The disadvantage of reducing the reflectance of the detector is that it can be difficult to obtain such a low reflectance as is required and that it is normally not possible to specify unambiguously due to the small values involved. In alternative solutions, an attempt has been made to use blocking filters that block the wavelength of the detecting laser radar. The disadvantage of blocking filters is that the wavelength of the laser radar must be known in advance.
There is thus a need to prevent the said emission of reflections out of the optical system without needing to work with or rely on being able to manufacture the detector or reticle with reflectance that is exceptionally low and difficult to specify. Similarly, there is a desire to avoid the use of blocking filters that require knowledge not only of the detecting equipment but also of the wavelength(s) at which the detecting equipment operates.