We propose a new method to realize the tunable unidirectional behavior using a heterostructure composed of a one-dimensional photonic crystal and a deformable liquid droplet. We can control the occurrence of the unidirectional behavior in the heterostructure by adjusting the voltage applied on the liquid system. It is demonstrated that when the voltage is not applied most of incident-wave energy can be transmitted through the heterostructure for backward lights. While the forward lights can’t be transmitted, if the voltage is high enough, the one-way behavior disappears. The applied voltage to control the one-way behavior may be relatively low. Thereby, we can expect that the heterostructure may have potential applications in optical devices.Highlights► We study the tunable unidirectional behavior using a heterostructure. ► The heterostructure is composed of a one-dimensional photonic crystal and a deformable liquid droplet. ► When the voltage is not applied the one-way phenomenon is obvious. ► If the voltage is high enough, the one-way behavior disappears.

The controllable behavior of optical Tamm state (OTS) is investigated in a heterostructure with nematic liquid crystal (NLC). By changing the external fields (electric field and temperature), the orientation of NLC’s molecules can be modified. It offers us an effective way to control the optical properties of the optical Tamm state. We obtain the critical condition for the appearance of the optical Tamm state. Our theoretical analysis and numerical simulations show that through choosing appropriate parameters we can not only change the frequency position of the optical Tamm state, but also realize the disappearance of the OTS.Highlights► We study optical Tamm states in a heterostructure with nematic liquid crystal. ► The frequency position of the optical Tamm state can be tuned by modifying applied voltage. ► The appearance of the optical Tamm state is controllable.

The microwave transmission characteristics of magnetic photonic band-gap (MPBG) materials, in which the periodic structures are composed of alternating layers of polycarbonate with and without ferromagnetic nanowires, are studied. We present a theoretical method to investigate the transmission spectra of the MPBG material. The band-gap effect varies with the periodic parameters of the MPBG structure. Our calculation can describe well the experimental measurement value. The influence of the applied static magnetic field on the MPBG and the ferromagnetic resonance phenomenon has been studied.

We propose a new method to realize the tunable unidirectional behavior using a heterostructure composed of a one-dimensional photonic crystal and a deformable liquid droplet. We can control the occurrence of the unidirectional behavior in the heterostructure by adjusting the voltage applied on the liquid system. It is demonstrated that when the voltage is not applied most of incident-wave energy can be transmitted through the heterostructure for backward lights. While the forward lights can’t be transmitted, if the voltage is high enough, the one-way behavior disappears. The applied voltage to control the one-way behavior may be relatively low. Thereby, we can expect that the heterostructure may have potential applications in optical devices.Highlights► We study the tunable unidirectional behavior using a heterostructure. ► The heterostructure is composed of a one-dimensional photonic crystal and a deformable liquid droplet. ► When the voltage is not applied the one-way phenomenon is obvious. ► If the voltage is high enough, the one-way behavior disappears.