New avenues for light-matter interaction: Parity-time symmetry and non-ergodic behaviour of gain-loss transducer arrays

We investigate the use of gain and loss added to various structures in a Parity-Time (PT) symmetric fashion: firstly, in an otherwise canonical co-directional coupler, we attempt to optimize the total amount of loss needed for a switching operation by using a local modulation of gain. Secondly, we interrogate the possible statistical consequence of using multiplicative process in series. Fluctuations of gain and loss in series gives rise to Geometric Brownian Motions (GBM), that may exhibit non-ergodic behavior in some limits. We explore generically the possible application to arrays of transducers where by transduction would stem from a modulation of gain or loss.