Operating in both directions. bidirectional couplers split or combine light the same way when it passes through them in either direction. bidirectional transmission sends signals in both directions, sometimes through the same fiber.
A two-layer neural network where each layer provides input to the other layer, and where the synaptic matrix of layer 1 to layer 2 is the transpose of the synaptic matrix from layer 2 to layer 1. see also: bidirectional associative memory.
