Research on dynamic control of Goos-Hänchen shifts of dual-band beams based on quasi-bound states in the continuum

Abstract

Through numerical simulation, we obtain two different quasi-bound states in the continuum (Q-BICs) at telecommunication band in a graphene-containing compound periodic grating waveguide structure by breaking the symmetry of grating width. Based on the Q-BIC mechanism, giant enhanced Goos-Hänchen (GH) shift with more than three orders of wavelength can be realized in dual bands. Due to the electro-optical properties of graphene, the dynamic adjustable shift effect is realized by changing its Fermi level. Finally, we design a grating structure that can realize giant GH shift, and demonstrate its excellent angular sensing performance (the sensitivity up to 10⁸ μm/deg) in wide angle range, which has great potential for signal amplification and angle sensing applications in reality.