Tunable low-threshold bistable Goos-Hänchen shift and Imbert-Fedorov shift using long-range graphene surface plasmons within the terahertz region.

An analytical exploration of bistable spatial and angular lateral shifts at terahertz radiation in a multilayered long-range graphene surface plasmon resonant configuration is proposed with a Kerr polymer at a ultra-low threshold of 200W/cm2 for low Fermi energy at 1 ps relaxation time. Here, spatial Goos-Hänchen shift is observed 10 times larger than the previously reported papers. The hysteretic behavior of the spatial and angular Imbert-Fedorov shift by tuning the incident electric field and tunability of the threshold intensities is also realized, which has not been previously reported. The proposed idea explores new avenues in lateral-shift-based optical switches and optical sensors.