Optical Tamm States in a Metal–Distributed Bragg Reflector Structure Incorporating a Monolayer MoS2

This study explores the tunable characteristics of optical Tamm states (OTS) in a metal–distributed Bragg reflector (DBR) structure integrated with a monolayer of molybdenum disulfide (MoS2). Through finite element simulations, we demonstrate that incorporating MoS2 enhances electromagnetic field localization at the metal–DBR interface, facilitating enhanced exciton–photon interaction. As the number of DBR periods increases, the OTS resonance wavelength undergoes a blue shift and eventually stabilizes, which indicates a wavelength-locking behavior. Under external bias, the locking threshold is lowered, and the resonance wavelength exhibits a nearly linear blue shift of approximately ~1 nm/V. Moreover, absorptance varies non-monotonically with the metal thickness, reaching over 99% at a thickness of 25 nm, due to the combined effects of plasmonic confinement and MoS2 excitonic enhancement. These findings demonstrate the potential of this structure for application in tunable photonic devices such as optical filters and modulators.