Laser sensor having a block ring activity

• US 20070133001A1
• Filed: 12/04/2006
• Published: 06/14/2007
• Est. Priority Date: 09/12/2001
• Status: Abandoned Application

• Current Assignee: Honeywell International Inc.
• Original Assignee: Honeywell International Inc.
• Inventors: Thorland, Rodney, Cabuz, Eugen, Cox, James, Cole, Barrett
• Application Number:
  US11/633,872
• Publication Number:
  US 20070133001A1
• Time in Patent Office: Days
• US Class Current: 356/437
• CPC Class Codes: G01J 3/42 Absorption spectrometry; Double beam spectrometry; Flicker spectrometry; Reflection spectrometry beam switching arrangements G01J3/08
• CPC Class Codes: G01N 2021/0378 Shapes
• CPC Class Codes: G01N 2021/1704 in gases
• CPC Class Codes: G01N 2021/399 Diode laser
• CPC Class Codes: G01N 21/03 Cuvette constructions
• CPC Class Codes: G01N 21/0303 Optical path conditioning in cuvettes, e.g. windows; adapted optical elements or systems; path modifying or adjustment G01N21/031 - G01N21/15 take precedence
• CPC Class Codes: G01N 21/031 Multipass arrangements
• CPC Class Codes: G01N 21/39 using tunable lasers

Abstract

A sensitive fluid sensor for detecting fluids and particularly trace fluids. The sensor may be adjustable for detecting fluids of various absorption lines. To effect such adjustment, a tunable laser may be used. The laser may non-tunable with a cavity having moveable mirror(s) for tuning. The laser may be an edge emitting diode, a VCSEL or other tunable on on-tunable source. The detection apparatus of the sensor may incorporate a sample cell through which a laser light may go through. The sample cell may include a tunable ring cavity block. There may be a photo detector or detectors proximate to the ring cavity. The lasers and detectors may be to electronics and/or a processor.

Claims

1. A sensor system comprising:

a cavity having a ring-like optical path for light propagation;

a tunable laser source for providing light into the optical path of the block cavity; and

a detector for detecting light in the block cavity; and

wherein the cavity is a block of material comprising a plurality of bores connected end to end as the ring-like optical path in the block.

2. The system of claim 1, further comprising:

readout electronics connected to the detector; and

wherein the readout electronics comprise a dual JFET charge amplifier.

3. The system of claim 1, further comprising:

control electronics connected to the tunable laser; and

a data acquisition and analysis circuit connected to the detector.

4. The system of claim 1, further comprising mirrors situated where the bores are connected end to end.

5. The system of claim 1, further comprising a conveyance device connected to the cavity for conveying a gas to and/or from the cavity.

6. The system of claim 1, further comprising:

a first window situated at a first position in a portion of the optical path; and

a second window situated at a second position in the portion of the optical path; and

wherein the first and second windows provide a compartment in the optical path sealed off from the rest of the optical path.

7. The system of claim 6, wherein the compartment is for holding a sample fluid to be analyzed.

8. A sensor comprising:

a ring cavity having an optical path;

a light source optically connected to the optical path;

a detector optically connected to the optical path; and

a set of windows situated in the optical path to form a compartment in the optical path.

9. The sensor of claim 8, wherein the windows are Brewster windows.

10. The sensor of claim 8, further comprising a conveyance mechanism connected to the compartment.

11. The sensor of claim 8, further comprising:

at least one mirror in the optical path; and

wherein the at least one mirror is adjustable for tuning the optical path.

12. The sensor of claim 11, wherein the at least one mirror is adjustable for tuning the optical path to an absorption line of a fluid in the ring cavity.

13. The sensor of claim 8, wherein:

the ring cavity is a solid block of material;

the optical path comprises two or more tunnels in the block.

14. The sensor of claim 13, wherein

a mirror is situated at the end of each two tunnels;

and

at least one mirror is adjustable in position for tuning the optical path.

15. The sensor of claim 8, wherein the light source is tunable to an adsorption line of a sample fluid in the compartment.

16. A system for sensing comprising:

a cavity having a plurality of light paths proximately associated together as legs of a polygon;

a mirror situated at a pair of ends of each pair of light paths, for reflecting light from one light path to another light path; and

a light source for providing light into at least one light path;

a detector for detecting light from at least one light path; and

wherein the cavity is formed out of a block of material.

17. The system of claim 16, further comprising a pair of windows in at least one light path to form a space in the light path sealed off from the light path outside of the space and sealed off from the other light paths.

18. The system of claim 16, wherein at least one mirror situated at a pair of ends of a light path is adjustable for tuning the cavity.

19. The system of claim 17, wherein the light source is tunable to an absorption line of a sample fluid in the space in the light path.

20. The system of claim 18 further comprising:

control electronics connected to the at least one adjustable mirror situated at a pair of ends of a light path; and

readout electronics connected to the detector; and

wherein the readout electronics comprises a dual FET amplifier.