We study the sensing properties of an intensity-modulated fiber-optic surface plasmon resonance (SPR)sensor using radially polarized beam (RPB).Because of the rotational symmetry of fiber and RPB,surfaceplasmon can be excited more efficiently atthe sensor surface,which results in an obvious improvement ofthe sensitivity.Our experiments demonstrate that the sensitivity in the case of RPB illumination is threetimes higher than that of linearly polarized beam illumination.
