Passive $\mathcal{P}\mathcal{T}$-symmetric couplers without complex optical potentials

Yi-Chan Lee, Jibing Liu, You-Lin Chuang +2

In addition to the implementation of parity-time ($\mathcal{P}\mathcal{T}$)-symmetric optical systems by carefully and actively controlling the gain and loss, we show that a $2\times 2$ $\ma…