A method for influencing electromagnetic radiation in a frequency range between 0.1 and 10 terahertz includes providing a planar modulator having a matrix of at least 10×10 individual, active planar elements. Each planar element has a diameter between 5 μm and 100 μm. The planar elements are individually controlled using a central control unit such that each planar element assumes a respective one of at least two states in accordance with the control so as to influence the radiation.