Storage-type electro-optical modulator

A storage-type electro-optical modulator, designed for modulating a radiated energy beam under the control of electrical input signals, said modulator comprising:

• a plate of homogeneous material capable of switching, under the action of an electric field, from a first stable state exhibiting certain optical properties to a second state exhibiting different optical properties;
• said plate having two large faces and being equipped, parallel to one of said faces, with a first network of parallel coplanar electrodes interconnected for forming two interdigital comb structures, and with a second network of distinct coplanar electrodes interleaved with those of the first network;
• said plate furthermore being equipped, parallel to the other of said faces and at the opposite side to said first and second networks, with a third network of distinct coplanar electrodes parallel with a direction making an angle with the direction of the electrodes of said second network;
• the electrodes of said second and third networks being constituted by a photoconductive material transparent to said radiated energy beam;
• said modulator further comprising illuminating means, provided to drive conductive said photoconductive material during a phase of selective application of said electrical input signals to the electrodes of said second and third networks, and electrical erase means energizing said first network of parallel coplanar electrodes during an erase phase, means being provided for shutting off said illumination means during said erase phase.