METHOD OF FABRICATING AN OPTICAL ANALYSIS DEVICE COMPRISING A QUANTUM CASCADE LASER AND A QUANTUM DETECTOR

• US 20100029026A1
• Filed: 07/31/2009
• Published: 02/04/2010
• Est. Priority Date: 08/01/2008
• Status: Abandoned Application

• Current Assignee: Thales SA
• Original Assignee: Thales SA
• Inventors: Berger, Vincent, Carras, Mathieu
• Application Number:
  US12/533,429
• Publication Number:
  US 20100029026A1
• Time in Patent Office: Days
• US Class Current: 438/24
• CPC Class Codes: B82Y 20/00 Nanooptics, e.g. quantum optics or photonic crystals
• CPC Class Codes: G01S 7/4811 common to transmitter and receiver
• CPC Class Codes: H01L 31/035236 Superlattices; Multiple quantum well structures
• CPC Class Codes: H01L 31/173 formed in, or on, a common substrate
• CPC Class Codes: H01S 5/0262 Photo-diodes, e.g. transceiver devices, bidirectional devices H01S5/0265 takes precedence
• CPC Class Codes: H01S 5/3402 intersubband lasers, e.g. transitions within the conduction or valence bands

Abstract

The invention relates to a method of fabricating an optical device for analysing a scene, comprising an emitter and a detector in the mid-infrared or far-infrared, characterized in that it comprises:

• • the production of a stack of semiconductor layers grown epitaxially on the surface of a semiconductor substrate, certain layers of which are doped;
  • the production of a first, quantum cascade laser emission device (L) emitting an analysis beam in the mid-infrared or far-infrared, from a first level called the emission level, into the stack of semiconductor layers; and
  • the production of a second, quantum detector device (D) capable of detecting a beam backscattered by the scene to be analysed, at the same level in the stack as the emission level.

Claims

1. A method of fabricating an optical device for analysing a scene, comprising an emitter and a detector in the mid-infrared or far-infrared, characterized in that it comprises:

the production of a stack of semiconductor layers grown epitaxially on the surface of a semiconductor substrate, certain layers of which are doped;

the production of a first, quantum cascade laser emission device (L) emitting an analysis beam in the mid-infrared or far-infrared, from a first level called the emission level, into the stack of semiconductor layers; and

the production of a second, quantum detector device (D) capable of detecting a beam backscattered by the scene to be analysed, at the same level in the stack as the emission level.

2. Method of fabricating an optical analysis device according to claim 1, wherein the analysis beam is directed towards the scene.

3. Method of fabricating an optical analysis device according to either of claims 1 or 2, including the production of a third, local oscillator device (LO) for performing a heterodyne detection.

4. Method of fabricating an optical analysis device according to claim 3, wherein the analysis beam is partly directed towards the scene and partly directed towards the detector.

5. Method of fabricating an optical analysis device according to claim 3, wherein the analysis beam is directed towards the detection device, the heterodyne detection being performed by interference between the analysis beam and a beam generated by the scene to be analysed.

6. Method of fabricating an optical analysis device according to claims 1 or 2, wherein the first and second devices are produced within a single stack of layers by an etching operation within said stack of semiconductor layers.

7. Method of fabricating an optical analysis device according to claims 1 or 2, wherein the first and second devices are produced at the same location in the stack of semiconductor layers and are activated in succession by specific control means.

8. Method of fabricating an optical analysis device according to claims 1 or 2, including the production of a diffracting device coupling onto the quantum cascade laser for making the light exit at normal incidence to the plane of the semiconductor layers.

9. Method of fabricating an optical analysis device according to claims 1 or 2, including the production of a diffracting device coupling onto the quantum detector for coupling the light at normal incidence to the plane of the semiconductor layers.

10. Method of fabricating an optical analysis device according to claims 1 or 2, wherein the optical device is intended for analysing gaseous species.

11. Method of fabricating an imaging system, comprising the production of a matrix of optical analysis devices according to claims 1 or 2, distributed in a matrix arrangement on the surface of a semiconductor substrate.

12. Method of fabricating a multispectral analysis system, comprising the production of a number of optical analysis devices according to claims 1 or 2 and wherein each device emits at a specific wavelength.

13. Method of fabricating a multispectral analysis system according to claim 12, wherein the variation in specific wavelength is obtained by varying the characteristics of each emission device.