A small passive electro-optic EMP sensor with the frequency range from 0.1 Hz to 700 MHz has been developed. This sensor can detect the field strength from 0.5 V/m to about 3000 V/m using different length of dipole antenna. The small probe size and all-dielectric fiber-optic cabling of the passive electro-optic probe allows for non.-intrusive pulsed E-field measurement in small enclosure or complicated electromagnetic environments.