Two right and left optical waveguides are provided so as to pass through a first directional coupler, a phase shifter, and a second directional coupler and so that directional couplers are provided in the first directional coupler portion and the second directional coupler portion. Array configuration allows accurate and repeatable configurations suited to studio and field use. In particular embodiments, a station that is either originating or forwarding a frame can insert its own OASS into the frame before transmitting it and a client station that receives a frame can forward it only if its own OASS exceeds the frame-enclosed OASS, by at least a predetermined amount. The present invention also includes methods and compositions employing nuclear localization signals for enhanced nuclear transport and expression of DNA.