Reflektor fuer elektromagnetische Strahlung

In summary, the invention relates to a reflector for electromagnetic radiation of wavelengths <lambda> with controllable degree of reflection and/or controllable transmissivity, comprising a first and a second reflection coating and an at least partially transparent non-electron-conducting intermediate coating arranged between the two reflection coatings and for the electromagnetic radiation of wavelength <lambda>, the thickness of said intermediate coating being <lambda>/4 or a whole-interger multiple of <lambda>/4, whereby at least one of the two reflection coatings is at least a partially transparent coating for the electromagnetic radiation of wavelength <lambda>, and the electrical resistance of the said layer determining its absorptivity and/or reflectivity for electromagnetic radiation of wavelength <lambda> is electrically controllable.