2 2 optical switch by embedding parity-time symmetric coupler in multi-mode interference based Mach-Zehender structure

In this article, an optical switch has been proposed and simulated by designing and embedding a parity-time (PT) symmetric coupler inside one of the arms of a multi-mode interference (MMI) based Mach-Zehnder. The whole structure consists of two MMI couplers at the beginning and end of the structure so that they are connected to each other through two passive waveguides, also a PT-symmetric coupler embedded in one of the arms. All elements in the proposed switch are linear and based on PT-symmetric coupler status; optical switch operates in two passive (without gain/loss) and active (with gain/loss) states. The suggested switch finds the extinction ratio and for active and passive states, respectively. Furthermore, regarding the simulation results, the insertion losses are given rise to low values for different gates. In this article, an optical switch has been proposed and simulated by designing and embedding a parity-time (PT) symmetric coupler inside one of the arms of a multi-mode interference (MMI) based Mach-Zehnder. The whole structure consists of two MMI couplers at the beginning and end of the structure so that they are connected to each other through two passive waveguides, also a PT-symmetric coupler embedded in one of the arms. All elements in the proposed switch are linear and based on PT-symmetric coupler status; optical switch operates in two passive (without gain/loss) and active (with gain/loss) states. The suggested switch finds the extinction ratio and for active and passive states, respectively. Furthermore,