LIQUID CRYSTAL DIFFRACTION GRATING

• US 3,843,231 A
• Filed: 02/14/1973
• Issued: 10/22/1974
• Est. Priority Date: 04/22/1971
• Status: Expired due to Term

• Current Assignee: Guy Labrunie, Jacques Robert, Jean-Claude Deutsch, Joseph Borel
• Original Assignee: Guy Labrunie, Jacques Robert, Jean-Claude Deutsch, Joseph Borel
• Inventors: Borel, Joseph, Deutsch, Jean-Claude, Labrunie, Guy, Robert, Jacques
• Primary Examiner(s): Bauer, Edward S.
• Application Number:
  US05/332,286
• Time in Patent Office: 615 Days
• Field of Search: 350/16LC,162R,162ZP
• US Class Current: 349/202
• CPC Class Codes: G02F 1/292 by controlled diffraction or phased-array beam steering controlled diffraction for optical switching G02F1/31
• CPC Class Codes: G02F 1/31 Digital deflection, i.e. optical switchingG02F1/33 takes precedence

Abstract

The device comprises at least one liquid-crystal cell placed on the path of the beam and constituted by a film of liquid crystals interposed between two walls provided with electrodes between which a potential difference can be applied by suitable means. The incidence of the light beam is oblique with respect to the first wall-liquid crystal interface which is encountered. Use is made of liquid crystals for which the direction of propagation of the light beam is dependent on the potential difference applied between the electrodes.

Claims

1. A DEVICE FOR DEFLECTING A LIGHT BEAM, COMPRISING AT LEAST ONE LIQUID-CRYSTAL CELL PLACED ON THE PATH OF SAID BEAM AND CONSTITUTED BY A FILM OF LIQUID CRYSTALS INTERPOSED BETWEEN TWO WALLS FITTED WITH ELECTRODES BETWEEN WHICH A POTENTIAL DIFFERENCE CAN BE APPLIED BY SUITABLE MEANS, WHEREIN THE INCIDENCE OF SAID LIGHT BEAM IS OBLIQUE WITH RESPECT TO THE FIRST WALL-LIQU CRYSTAL INTERFACE WHICH IS ENCOUNTERED AND WHEREIN USE IS MADE OF LIQUID CRYSTALS FOR WHICH THE REFRACTIVE INDEX IS DEPENDENT ON THE POTENTIAL DIFFERENCE APPLIED BETWEEN SAID ELECTRODES, WHEREIN THE ELECTRODES ARE EACH FORMED BY AN ARRAY OF IDENTICAL CONDUCTIVE AND TRANSPARENT STRIPS BEING EQUAL TO THE THE DISTANCE BETWEEN TWO ADJACENT STRIPS BEING EQUAL TO THE WIDTH OF THE STRIPS AND EACH STRIP OF ONE OF SAID ARRAYS BEING LOCATED OPPOSITE TO ONE STRIP OF THE OTHER ARRAY, AND MEANS FOR ESTABLISHING A POTENTIAL DIFFERENCE BETWEEN THE TWO ELECTRODES, THE ESTABLISHMENT OF SAID POTENTIAL DIFFERENCE BEING SUCH AS TO FORM A DIFFRACTION PATTERN BY TRANSMISSION.

2. A device according to claim 1, wherein the angle of incidence of said light beam on said entrance window and the physical characteristics of said device make it possible to produce a '"'"''"'"''"'"''"'"'Bragg reflection'"'"''"'"''"'"''"'"'.