Micro gas cell array device and method
A device and method for the detection of one or more gases is disclosed. A MEMS structure comprising a micro gas cell array is provided comprising one or more micro gas cells having a predetermined gas therein. The micro gas cells define an optical path therethrough and may comprise a micro lens. Electromagnetic energy from a scene is collected and passed through one or more micro gas cells whereby electromagnetic energy emitted or reflected from a gas of interest in a scene is absorbed by a substantially identical gas contained within a micro gas cell. In this manner, the micro gas cell acts as a spectral filter. The electromagnetic outputs of the micro gas cells, which may comprise one or more spectrally inert micro gas cells, are received by one or more detector elements such as a photon detector array. The ratio of the outputs of the related detector elements are computed by processing electronics, resulting in the identification of the gas of interest.
1. A sensor system comprising:
a structure comprising a plurality of sealed gas volumes having a predetermined gas disposed therein and defining an optical path there through,
a micro lens disposed along the optical path defined by at least one of the sealed gas volumes, and,
optical scanning means for scanning a beam into at least one of the sealed gas volumes.
2. The sensor system of claim 1 wherein at least one of the predetermined gases is disposed within one of the sealed gas volumes at a pressure greater than one atmosphere.
3. The sensor system of claim 1 wherein at least one of the sealed gas volumes comprises a spectrally inert gas therein.
4. The sensor system of claim 1 wherein at least one of the sealed gas volumes comprises at least a partial vacuum therein.
5. The sensor system of claim 1 wherein the predetermined gases in at least two of the sealed gas volumes are substantially identical.
6. The sensor system of claim 1 further comprising:
collection optics means, a detector element having an electronic output, and,
processing electronics for the processing of the electronic output.
7. The sensor system of claim 1 further comprising:
collection optics means, optical scanning means, a photon detector array comprising a plurality of detector elements having an electronic output, and,
processing electronics for the processing of the electronic output.
8. The sensor system of claim 7 further comprising beam splitting means.
9. The sensor system of claim 7 wherein at least one of the predetermined gases comprises CO 2 .
10. The sensor system of claim 7 wherein at least one of the predetermined gases comprises CO.
11. The sensor system of claim 7 wherein at least one of the predetermined gases comprises H 2 S.
12. The sensor system of claim 7 wherein at least one of the predetermined gases comprises N 2 O.
13. The sensor system of claim 7 wherein at least one of the predetermined gases comprises SO 2 .
14. The sensor system of claim 7 wherein at least one of the sealed gas volumes has a hydrocarbon therein.
15. A method for identifying a gas comprised of the steps of:
collecting electromagnetic radiation emitted or reflected from a scene,
directing at least a first portion of the electromagnetic radiation through a micro lens and through a first micro gas cell having a predetermined gas therein,
directing at least a second portion of the electromagnetic radiation through a micro lens and through a second micro gas cell,
receiving the first portion of electromagnetic energy upon a first detector element having a first detector output,
receiving the second portion of electromagnetic energy upon a second detector element having a second detector output, and,
comparing the first detector output to the second detector output to define a ratio between the first detector output and the second detector output.
16. The method of claim 15 wherein the directing of the first portion of the electromagnetic energy or the second portion of the electromagnetic energy comprises the use of beam splitting means.
17. The method of claim 15 wherein the directing of the first portion of the electromagnetic energy or the second portion of the electromagnetic energy comprises the use of optical scanning means.