We report our recent study of ultrafast electro‐optic field sensors for the coherent measurement of freely propagating subpicosecond pulsed electromagnetic waves (THz beams). The sensitivity and bandwidth of these electro‐optic sensors are comparable with the conventional ultrafast photoconductive dipole antennas. The simplicity of the detection geometry and capability of optical parallel processing make these sensors suitable for real‐time 2D subpicosecond far‐infrared imaging. ©1996 American Institute of Physics.