Electro-optical method and device for modulation of light are presented providing a substantially balanced voltage-phase response of the device in two orthogonal polarization directions substantially irrespective of applied voltages. The device comprises a crystal material of a predetermined orientation of the plane of propagation of light therethrough, formed with at least one waveguide channel directed in a predetermined direction, and at least two electrodes accommodated at opposite sides of the waveguide channel. The substantially balanced voltage-phase response is achieved by shifting the electrodes relative to the axis of the waveguide channel a predetermined distance in a certain direction. The device may be designed so as to operate as a phase modulator or an amplitude modulator.