We present the applicability of pigtailed non-linear optical microcavities to perform non invasive vectorial characterization of electric (E) field, especially in guided configuration. Those sensors are based on Pockels' effect, which consists in additional birefringence induced by an applied E field in certain non-centrosymetric crystals [1], called electro-optic (EO) crystals. By sandwiching the EO crystal between two dielectric mirrors, the E-field induced phase modulation of the laser beam is then enhanced thanks to the resonance of the Fabry-Pérot (FP) cavity [2, 3]. Moreover, choosing a working wavelength on the steepest slope of one of the cavity resonance peaks leads to a direct amplitude modulation of the laser, this latter one being directly proportional to the applied E field. The vectorial behavior of the measurement (measurement of a given E field component) is intrinsically linked to the relation that links the crystal refractive indices variation to the applied E field through a scalar product with the sensitivity vector of the EO crystal [4]. Developed sensors are based on LiNbO 3 optical waveguides obtained by titanium diffusion along to the Y axis of the crystal. The waveguide is finally embedded between two multilayer dielectric mirrors to obtain the FP microcavity (∼ 1mm 3), coupled to a polarization maintaining fiber to perform remote measurements (up to a few 10 meters). Those transducers have already been studied in term of sensitivity and a lowest measurable E field of 1V·m -1·Hz -1/2 has been achieved. They are also suitable for very high field strength measurement and we here demonstrate some time domain measurements of disruptive E field. Longitudinal spatial resolution is determinate by the length of the microcavity. Transversal spatial resolution has been estimated to less than 50 μm by measuring fringing E-field above interdigitated strip lines. The bandwidth is linked to the inner-cavity photons life time and reaches a few tens of GHz. Two dimensional E-field mapping of fringing fields have been achieved in the frequency domain. Invasiveness of the sensors (influence of the probe on the electric signal propagation) is very low and quantitative estimations of this latter one are in progress. They are measured using common microwave differential techniques exploiting the EO-sensor induced variation of phase and amplitude of both transmitted and reflected microwave signals.