Tunable Goos-Hänchen Shift in Symmetric Graphene-Integrated Bragg Gratings

Area of Science:

• Optics and Photonics
• Materials Science
• Nanotechnology

Background:

• The Goos-Hänchen (GH) effect describes the transverse spatial shift of a reflected light beam.
• Conventional Bragg gratings have limitations in achieving large GH shifts.
• Graphene's unique electronic properties offer potential for tunable optical devices.

Purpose of the Study:

• To theoretically analyze and enhance spatial Goos-Hänchen shifts in a novel Graphene-Integrated Bragg Grating (GIBG) structure.
• To explore the tunability of GH shifts using graphene and cavity parameters.
• To investigate the potential applications of GIBGs in sensing and adaptive optics.

Main Methods:

• Theoretical analysis of light propagation in symmetric GIBGs.
• Modeling GIBGs with monolayer graphene arrays as tunable couplers and dielectric resonant cavities.
• Optimization of cavity design parameters, including grating geometry and dielectric thickness.

Main Results:

• Achieved a significantly enhanced spatial GH shift of 1766λ, exceeding conventional limits.
• Demonstrated active control over GH shift magnitude and direction via graphene's chemical potential, grating geometry, and dielectric thickness.
• Identified optimal cavity designs for maximizing the GH shift.

Conclusions:

• Graphene-Integrated Bragg Gratings offer a powerful platform for achieving large, tunable Goos-Hänchen shifts.
• The proposed mechanism provides a pathway for developing high-sensitivity refractive index sensors.
• This technology holds promise for creating novel adaptive optical devices.