LIGHT MODULATOR

• US 3,656,836 A
• Filed: 06/26/1969
• Issued: 04/18/1972
• Est. Priority Date: 07/05/1968
• Status: Expired due to Term

• Current Assignee: Baudoin D.E. Cremoux, Pierre Leclerc
• Original Assignee: Baudoin D.E. Cremoux, Pierre Leclerc
• Inventors: de Cremoux, Baudoin, Leclerc, Pierre
• Primary Examiner(s): Wibert, Ronald L.
• Assistant Examiner(s): McGraw, V. P.
• Application Number:
  US04/836,783
• Time in Patent Office: 1,027 Days
• Field of Search: 331/94.5 350/160 250/211J 332/7.51
• US Class Current: 359/261
• CPC Class Codes: G02F 1/015 based on semiconductor elements having potential barriers, e.g. having a PN or PIN junction G02F1/03 takes precedence
• CPC Class Codes: H01S 3/1063 using a solid state device provided with at least one potential jump barrier

Abstract

The application of a voltage between the semiconductor and the conducting layers of a structure wherein said layers are separated by an insulator layer allow the modulation of a luminous radiation propagating through or reflected on said structure.

Claims

1. A device for modulating a beam of radiation having a predetermined wavelength comprising:

a substrate of doped semiconductor material partially transparent to said radiation and having at least two valence bands, and said beam of radiation of said predetermined wavelength causing the transition of electrons from a lower valence band to an upper valence band;

an insulating layer extending over said substrate;

a conductive layer extending over said insulating layer, and means for applying between said conductive layer and said substrate a modulating voltage, whereby the beam of radiation is modulated.

2. A device as claimed in claim 1, wherein said conductive layer is transparent to said radiation.

3. A device as claimed in claim 2, wherein said conductive layer is a semiconductor material.

4. A device as claimed in claim 3, further comprising antireflection coatings extending on said conductive layer and on said substrate respectively.

5. A device as claimed in claim 1, wherein said conductive layer reflects said radiation.

6. A device as claimed in claim 5, wherein a low reflectance film covers the exposed face of said substrate.

7. A device as claimed in claim 5, further comprising a second insulating layer deposited on said substrate, said substrate being sandwiched between said insulating layers, a second conductive layer extending over said second insulating layer, said conductive layers reflecting said radiations, and means for applying said modulating voltage to both conductive layers.

8. A device as claimed in claim 7, wherein at least one of said conductive layer partially reflects said radiation.

9. An amplitude modulated laser for emitting a beam of radiation having a predetermined wavelength comprising two mirrors for defining a laser cavity an active body of laser material between said mirrors, and a modulating device as claimed in claim 1, for modulating said beam of radiation positioned between one of said mirrors and said body of laser material.

10. An amplitude modulated laser device for emitting a beam of radiation having a predetermined wavelength comprising a modulating device as claimed in claim 5 for modulating said beam of radiation, a partially reflecting mirror, and an active body of laser material between said modulating device and said mirror, said modulating device and said mirror defining a laser cavity.