Double-state controllable optical switching through three tunnel-coupled quantum dots inside waveguide coupled photonic crystal microcavity

► Optical transmission properties of a new kind of combined system are investigated. ► A type of double-state controllable optical switching operation is proposed. ► The optical switching can work in a low-Q cavity, which allows more practical parameter range. ► The switching operation is controllability by the gate-assisted tunneling rates between QDs.