Adjustable enhanced Goos-Hänchen shift in a magneto-optic photonic crystal waveguide

We have presented adjustable enhanced Goos-Hänchen (GH) shift in a magneto-optical photonic crystal (MOPC) waveguide. The waveguide consists of a top layer of ferrite rods and a lower MOPC with opposite biased dc external magnetic fields (EMFs), and it supports both odd-like and even-like modes simultaneously. The simulation results show the odd-like mode can cause an enhanced negative GH shift, while the even-like mode can result in an enhanced positive GH shift. The physical reason for such negative and positive GH shifts is attributed to the efficient mode coupling and propagation behaviors of the electromagnetic (EM) wave in the waveguide. Furthermore, we have realized the switchable negative/positive GH shift by altering the direction combination of the EMFs. In addition, the magnitudes of both GH shifts can be adjusted by changing the strength of EMF or the width of the waveguide. These results provide new ways to control the transmission behaviors of EM wave and hold promise in applications such as detections, optical switches, and sensors.