Weak measurement of magneto-optical Goos-Hänchen effect.

As a lateral shift of reflected light beam from the optical interface, the Goos-Hänchen (GH) effect led to various practical applications in biosensing and optical field manipulations. Magneto-optical (MO) effect of dielectric or metal may bring flexible modulation for GH effect, which can be regarded as the magneto-optical Goos-Hänchen (MOGH) effect. In this paper, the GH and MOGH effects in a BK7 prism/Fe/Au waveguide enhanced by surface plasmon resonance (SPR) are demonstrated experimentally for the first time. By weak measurement, the GH and MOGH shifts are further amplified to facilitate their applications. By contrast, the results of theory and experiment are basically consistent. The maximum MOGH shift of the proposed BK7/Fe/Au waveguide achieves 120 μm when optimum thicknesses are chosen. As MOGH effect exhibits a higher sensitivity to the refractive index of sample than GH shift, it can be applied in refractive index detection. The demonstrated MOGH effect with advantages of high sensitivity and convenient control opens avenues for future applications with biosensors and functionally optical devices.