Magnetic tuning of liquid crystal dielectric metasurfaces.

Dielectric metasurfaces hold an exceptional potential for the next generation of tunable optical systems that find applications in sensing, ranging, and imaging. Here, we introduce and demonstrate magnetic field tuning of dielectric metasurfaces infiltrated with liquid crystals. To illustrate this concept, we show how the reorientation of liquid crystal induced by the magnetic field changes the spectrum of the resonant dielectric metasurface. This new magnetic-field tuning approach offers significant advantages over other liquid crystal tuning methods since it does not require pre-alignment or the fabrication of structured electrodes, which are both challenging when dealing with metasurfaces. Furthermore, there are no strict limitations on the thickness of liquid crystal cells. Importantly, our approach allows for gradual tuning of the resonances by changing the magnetic-field orientation and, thereby, shows good promise for highly tunable optical metadevices.