Analyzing Goos-Hänchen Shift on Dielectric Gratings

The Goos-Hänchen (GH) effect is a well-known optical phenomenon in which a light beam undergoing total internal reflection experiences a lateral shift between the incident and reflected beams. While studied for decades because of its unique physical properties, the GH effect has gained renewed interest with the emergence of plasmonic materials, metamaterials, and highly sensitive optical sensing technologies. Increasing the magnitude of the GH shift is particularly valuable, as sensor performance is directly linked to the achievable displacement.

This application note investigates the use of Guided Mode Resonance (GMR) to generate giant positive and negative Goos-Hänchen shifts in dielectric grating structures. The simulated configuration consists of a dielectric grating illuminated from the substrate side at an angle exceeding the critical angle, resulting in total internal reflection. When the incident light couples into a leaky guided mode within the grating, strong energy confinement and propagation occur inside the waveguide, producing significantly enhanced lateral beam shifts. The study also examines conditions under which negative Goos-Hänchen shifts arise, caused by leaky modes whose energy flow is opposite to the direction of wave propagation.

Using rigorous electromagnetic simulation, engineers can accurately model resonance behavior, optimize grating geometries, and predict the resulting GH shifts before fabrication. This enables the design of highly sensitive optical sensors for biochemical detection, thermal monitoring, wavelength measurement, and other precision photonic applications.

By combining advanced simulation with guided mode resonance design, engineers can accelerate the development of next-generation optical sensing devices that deliver enhanced sensitivity and improved performance through controlled Goos-Hänchen shift engineering.