A 2×2 spatial optical switch based on PT-symmetry

Opt Lett. 2011 Nov 15;36(22):4368-70. doi: 10.1364/OL.36.004368.

Abstract

We show a PT-symmetric coupler having an arm with a tunable gain and a no-loss arm when appropriately designed to possess reciprocal behavior, unlike its rivals having a fixed gain/loss arm, can perform as a tunable 2×2 spatial optical switch. The degree of the tunability equals the ratio of the coupler's length to the total coupling length.