Concept of a photon spatial switch based on an off-axis zone plate: experimental confirmation in the millimeter waves range

We present results of the experimental verification of a concept of the previously proposed all-optical wavelength-selective multichannel switch based on an off-axis Wood zone plate in the millimeter waveband without the use of micromechanical devices or non-linear materials. A laboratory prototype of such a device is considered and its main parameters are discussed. It is shown that the optical isolation of switched channels for the switch based on an off-axis zone plate can reach 15 dB at a frequency difference of 25 GHz in the frequency range of 93–136 GHz.