Device for the detection of multispectral infrared/visible radiation

• US 6,320,189 B1
• Filed: 07/13/1999
• Issued: 11/20/2001
• Est. Priority Date: 07/28/1998
• Status: Expired due to Term

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: Vilain, Michel, Ouvrier-Buffet, Jean-Louis, Beccia, Chantal
• Primary Examiner(s): Hannaher, Constantine
• Assistant Examiner(s): Israel, Andrew
• Application Number:
  US09/352,232
• Time in Patent Office: 861 Days
• Field of Search: 250/332, 250/330, 250/338.4
• US Class Current: 250/338.4
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0846 having multiple detectors for performing different types of detection, e.g. using radiometry and reflectometry channels
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: H01L 27/14669 Infrared imagers
• CPC Class Codes: H04N 23/11 for generating image signals from visible and infrared light wavelengths

Abstract

A device for the detection of multi-spectral infrared and visible radiation using a bolometric detector having at least one active layer and two control electrodes for the detection of both infrared and visible radiation, and also using at least one photodetector having at least two active layers and two control electrodes for detecting solely visible radiation. The device is uncooled, and the two detectors are superimposed and combined with one-another for forming the same sensitive element.

Claims

1. Device for the detection of multispectral infrared/visible radiation comprising:

at least one bolometric detector (I) having at least one active layer (10) and two control electrodes and ensuring the detection of IR and visible radiation and

at least one photoelectric detector (V) having at least two active layers (11, 12) and two control electrodes and solely ensuring the detection of visible radiation,

characterized in that the bolometric detector and the photoelectric detector are of the uncooled type and that they are superimposed and combined with one another to form the same sensitive element.

2. Device according to claim 1, wherein the sensitive element comprises a microbridge (4) connected to a multiplexing circuit (1) by support and connection means (5, 6, 8), characterized in that the microbridge incorporates active layers of the bolometric detector and the photoelectric detector (10, 11, 12), as well as their control electrodes (13, 14, 15).

3. Device according to claim 2, characterized in that the bolometric detector and the photoelectric detector have at least one common control electrode (14).

4. Device according to claim 2, characterized in that the active layers (10, 11, 12) of the photoelectric detector form a photodiode having a lower electrode (15) and an upper electrode (14), the latter also constituting one of the electrodes of the bolometric detector.

5. Device according to claim 4, characterized in that it has a type P⁺ a-Si:

H layer common to the two detectors, the photoelectric detector also having an intrinsic a-Si;

H layer and a type N⁺ a-Si;

H layer.

6. Device according to claim 3, characterized in that the active layers (11, 12, 16) of the photoelectric detector form an insulated photodiode.

7. Device according to claim 6, characterized in that the active layer (10) of the bolometric detector is of type P⁺ or N⁺ a-Si:

H or Vox or metal and the active layers of the photosensitive detector are of type P⁺ a-Si;

H, intrinsic a-Si;

H and type N⁺ a-Si;

H.

8. Device according to claim 3, characterized in that the active layers (11, 12, 23) of the photoelectric detector form a phototransistor.

9. Device according to claim 8, characterized in that the active layers of the photoelectric detector and the bolometric detector are of a-Si:

H with different doping levels.

10. Device according to claim 1, in which the sensitive element incorporates a microbridge (4) connected to a multiplexing circuit (1) by support and connection means (5, 6, 8), characterized in that the microbridge incorporates the active layer (9) and the bolometric detector control electrode (7) and in that the photoelectric detector (26) is placed beneath the microbridge facing the bolometric detector.

11. Device according to claim 10, characterized in that at least part of the microbridge is made from materials transparent to visible radiation.

12. Device according to claim 10, characterized in that the active layer and/or the electrodes of the bolometric detector have one or more holes ensuring the passage of visible radiation through the microbridge.

13. Device according to claim 10, in which the sensitive element has a reflector (3) placed beneath the microbridge and above the addressing circuit, characterized in that said reflector is made from a material reflecting infrared radiation and transparent to visible radiation.

14. Device according to claim 10, characterized in that the photoelectric detector is integrated into the multiplexing circuit.

15. Device according to claim 1, in which the sensitive element incorporates a microbridge (4) connected to a multiplexing circuit (1) by support and connection means (5, 6, 8), characterized in that the microbridge incorporates the active layer (9) and the electrodes (7) of the bolometric detector which forms, on the multiplexing circuit (1), reticulation zones, in which is inserted the photoelectric detector (27).

16. Device according to claim 1, characterized in that it has a plurality of identical, sensitive elements, joined to one another in order to form an array of sensitive elements.