BK7 glass has an unusual temperature-dependent refractive index and thickness, which provides a promising platform for uncovering the temperature-related optical phenomena and applications. Here, we theoretically demonstrate that monolayer graphene based BK7 glass grating structure has two Goos-Hänchen (GH) peaks with respective magnitudes of 2564λ and 1993λ, and their corresponding reflectances are also high. The electromagnetic field distribution in this structure directly reveals that the enhanced GH shifts can be ascribed to the excitation of the guide mode resonances in the waveguide dielectric layer below BK7 glass grating structure and their high reflectances are granted by the constructive interferences between the reflected waves. In addition, the magnitudes of the GH peaks can be controlled by the temperature of BK7 glass as well as the chemical potential of monolayer graphene. We also evaluate the temperature sensing property of this structure based on the GH shifts and find that its maximum temperature sensitivity can be up to 50017 μm/°C . The enhanced and controlled GH shift presented in monolayer graphene based BK7 glass grating structure shows promise for the applications, such as, optical sensors, temperature sensors, and optoelectronic detectors.

Recently, the dielectric gratings have been used in enhancing the Goos-Hänchen (GH) shifts of monolayer graphene. However, many of these structures are limited within single dielectric grating. Dual dielectric gratings are compelling candidates for the manipulation of the light-matter interaction owing to their flexible degree of freedom in geometrical parameters. Here, we present the GH shift of the reflected wave in the dual dielectric grating layers by using rigorous coupled-wave analysis (RCWA) and stationary phase method, where a monolayer graphene is placed on top of the lower dielectric grating layer and the upper and lower dielectric grating layers have different filling factors. It is found that a relatively large GH shift, with amplitude up to more than 8000 times of the incident wavelength, can be achieved in the dual dielectric grating layers with monolayer graphene due to the joint excitation of the guided mode resonance (GMR) in both the upper and lower dielectric grating layers. In addition, we can control the magnitude and position of GH shifts by changing chemical potential of monolayer graphene and the geometrical parameters of the dual dielectric grating layers. Our work opens a possibility for the improvement of the GH shift in the combined structure with the dual dielectric grating layers and the two-dimensional layered structure, which might enable the novel optoelectronic devices.

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