A voltage sensor capable of single-point or simultaneous multi-point
contactless voltage measurement has an electro-optic transducer, a
surface plasmon resonance (SPR) and an optical system. The electro-optic
transducer is operable to translate an electric field dependent on the
voltage in a device under test field to a variation in refractive index.
The surface plasmon resonance (SPR) transducer is juxtaposed with the
electro-optic transducer and is operable to translate the variation in
the refractive index of the electro-optic transducer to a variation in
reflectivity. The optical system is configured to illuminate the SPR
transducer with incident light at a surface plasmon resonance-inducing
angle of incidence and to detect light reflected by the SPR transducer at
a single point or at multiple points within a region.