Observation of strong transverse magneto-optical Kerr effect on surface plasmonic gratings

Strong transverse magneto-optical Kerr effect (TMOKE) on Au/Fe/Au surface plasmon (SP) gratings is demonstrated. Via the optimal design of this structure, the measured Kerr parameter is 0.03, which is 3 times larger than the maximal value ever reported on a plane magneto-optical SP substrate. Moreover, the Kerr parameter is very dispersive near the SP wavelength, which can be used for a high sensitive biosensor.