Photonic crystal based multi-channel rotary joint for electro-magnetic signals

A multi-channel electro-magnetic rotary joint for electro-magnetic signal transmissions comprising:

• A first collimator array with a rotary axis;
• A second collimator array with a rotary axis;
• A photonic crystal de-rotating mechanism;
• and
• Said first collimator array and said second collimator array are aligned with said rotary axes and relatively rotatable along said rotary axes and having a photonic crystal de-rotating mechanism positioned in the path between said first collimator array and said second collimator array, wherein is arranged for rotation around said rotary axes relative to each of said first and second collimator arrays at a rotary speed equal to one-half the relative rotational rate between said first and second collimator arrays;
• and a speed reduction mechanism for providing the rotation between said photonic crystal de-rotating mechanism and said first and second collimator array to rotate the photonic crystal de-rotating mechanism at a rotational rate half the rotational rate of said first and second collimator array;
• wherein said speed reduction mechanism is a gear mechanism with gear ration of 2:1, or any other passive mechanical system.