With the demand of ultrahigh-speed logic, there has been an emphasis on low-power design techniques. Reversible computing has been proposed as a possible alternative to address the energy dissipation problem. Thus, the reversible circuit implementation in optical domain gives a new dimension in ultrahigh-speed, low-power consumption of quantum computing. In this study, a design of reversible multiplexer using electro-optic effect of lithium niobate-based Mach–Zehnder interferometer is proposed. It is verified using a beam propagation method along with MATLAB simulation.