Routing optical signals

A method to route optical signals, comprising:

• applying at least one signal to a plurality of hollow metal waveguide optical switch arrays, each of the arrays comprising a plurality of optical input ports and a plurality of optical output ports, the input ports and the output ports for a first one of the arrays being arranged on a first plane, the input ports and the output ports for a second one of the arrays being arranged on a second plane, and the arrays being stacked such that the first and second planes are adjacent, wherein the first one of the arrays is to convey optical signals from a first communication device to a second communication device and the second one of the arrays is to convey optical signals from the second communication device to the first communication device, wherein the output ports of the first array are adjacent the input ports of the second array;
• and
• responding to the at least one signal by adjusting microelectromechanical reflectors in the first and second arrays to form optical pathways between the input ports and the output ports, such that corresponding input ports of the first and second arrays are in optical communication with corresponding output ports of the first and second arrays.