INFRARED DETECTOR BASED ON SUSPENDED BOLOMETRIC MICRO-PLATES

• US 20120153151A1
• Filed: 11/15/2011
• Published: 06/21/2012
• Est. Priority Date: 12/17/2010
• Status: Active Grant

• Current Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Original Assignee: Commissariat a L'Energie Atomique (AES Corporation)
• Inventors: DUMONT, Geoffroy, BOUTAMI, Salim, IMPERINETTI, Pierre, MARY, Alexandre, POCAS, Stéphane, RABAUD, Wilfried, ARNAUD, Agnès
• Granted Patent: US 8,895,924 B2
• Time in Patent Office: Days
• US Class Current: 250/338.1
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01J 5/02 Constructional details
• CPC Class Codes: G01J 5/023 Particular leg structure or construction or shape; Nanotubes
• CPC Class Codes: G01J 5/024 Special manufacturing steps or sacrificial layers or layer structures
• CPC Class Codes: G01J 5/08 Optical arrangements
• CPC Class Codes: G01J 5/0803 Arrangements for time-dependent attenuation of radiation signals
• CPC Class Codes: G01J 5/0806 Focusing or collimating elements, e.g. lenses or concave mirrors
• CPC Class Codes: G01J 5/0815 Light concentrators, collectors or condensers
• CPC Class Codes: G01J 5/20 using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
• CPC Class Codes: G02B 2207/101 Nanooptics
• CPC Class Codes: G02B 5/1809 with pitch less than or comparable to the wavelength
• CPC Class Codes: G02B 5/1885 Arranged as a periodic array

Abstract

This bolometric array detector for detecting electromagnetic radiation in a predetermined range of infrared or terahertz wavelengths comprises a substrate and an array of bolometric micro-plates for detecting said radiation that are suspended above the substrate by support arms. It comprises a metallic membrane located above and around each micro-plate and in which openings are formed; said openings in metallic membrane are periodically located in it along at least one predetermined axis with a period equal to or less than

$\frac{\lambda }{n},$

where λ is a wavelength in the wavelength range that is to be detected and n is the average refraction index of the medium that separates the micro-plate from metallic membrane.

Claims

1. A bolometric array detector for detecting electromagnetic radiation in a predetermined range of infrared or terahertz wavelengths comprising a substrate and an array of bolometric micro-plates for detecting said radiation, said micro-plates being suspended above the substrate by means of support arms,

wherein said detector comprises a metallic membrane placed on top and around each micro-plate and in which openings are formed;

and

wherein the openings formed in the metallic membrane are periodically located in said membrane along at least one predetermined axis with a period equal to or less than

2. The bolometric array detector as claimed in claim 1, wherein the width of the openings along the, or each, predetermined axis increases from a location on the metallic membrane positioned above a central area of micro-plate towards the periphery of said metallic membrane.

3. The bolometric array detector as claimed in claim 2, wherein the width of the openings at said location on the membrane satisfies the equation

4. The bolometric array detector as claimed in claim 1, wherein the width of the openings is constant and between

5. The bolometric array detector as claimed in claim 1, wherein the metallic membrane is located above the micro-plate at a distance of less than

6. The bolometric array detector as claimed in claim 1, wherein the period is substantially equal to

7. The bolometric array detector as claimed in claim 1, wherein the metallic membrane has a thickness of less than

8. The bolometric array detector as claimed in claim 1, wherein the metallic membrane rests on a support layer which is at least partially transparent to the wavelength of the electromagnetic radiation to be detected, especially a dielectric or semiconductor layer.

9. The bolometric array detector as claimed in claim 8, wherein the openings in the metallic membrane are also realized in the support layer.

10. The bolometric array detector as claimed in claim 8, wherein the support layer is solid and forms, together with lateral support walls that surround the micro-plate, a hermetic enclosure in which said micro-plate is positioned.

11. The bolometric array detector as claimed in claim 1, wherein the metallic membrane is supported by a structure that rests on the support arms of the micro-plate.

12. The bolometric array detector as claimed in claim 1, wherein the openings in the metallic membrane are parallel slits.

13. The bolometric array detector as claimed in claim 1, wherein the openings in the metallic membrane are square or circular.

14. The bolometric array detector as claimed in claim 1, wherein the metallic membrane consists of aluminum, titanium, titanium nitride, copper or tungsten.