Wide spectral range spectrometer

• US 9,182,278 B2
• Filed: 03/14/2013
• Issued: 11/10/2015
• Est. Priority Date: 03/14/2013
• Status: Active Grant

• Current Assignee: SciAps, Inc.
• Original Assignee: SciAps, Inc.
• Inventors: Day, David
• Primary Examiner(s): Punnoose, Roy M
• Application Number:
  US13/826,102
• Publication Number:
  US 20140268127A1
• Time in Patent Office: 971 Days
• Field of Search: 356/328, 356/330, 356/310, 356/326
• US Class Current: 1/1
• CPC Class Codes: G01J 2003/1282 Spectrum tailoring
• CPC Class Codes: G01J 3/0208 using focussing or collimating elements, e.g. lenses or mirrors; performing aberration correction
• CPC Class Codes: G01J 3/021 using plane or convex mirrors, parallel phase plates, or particular reflectors
• CPC Class Codes: G01J 3/0229 using masks, aperture plates, spatial light modulators or spatial filters, e.g. reflective filters
• CPC Class Codes: G01J 3/0291 Housings; Spectrometer accessories; Spatial arrangement of elements, e.g. folded path arrangements
• CPC Class Codes: G01J 3/14 using refracting elements, e.g. prisms G01J3/18, G01J3/26 take precedence prisms per se G02B5/04
• CPC Class Codes: G01J 3/16 with autocollimation
• CPC Class Codes: G02B 26/0833 the reflecting element being a micromechanical device, e.g. a MEMS mirror, DMD G02B26/0825 takes precedence; micromechanical devices in general B81B

Abstract

Featured is a spectral analysis method and a wide spectral range spectrometer including a source of electromagnetic radiation and an optical subsystem configured to disperse radiation into a plurality of wavelengths. A pixilated light modulator receives the radiation wavelengths and is configured to direct one or more selective wavelengths to a sample.

Claims

1. A enhanced spectral range system comprising:

a source of electromagnetic radiation;

an optical subsystem configured to disperse said radiation into a plurality of wavelengths;

a pixilated light modulator receiving said radiation wavelengths and configured to direct one or more selective wavelengths to a sample;

a single element detector oriented to receive radiation reflected from the sample, said single element detector sensitive over a wavelength range of approximately 400-2500 nm; and

,

a controller configured to control the pixilated light modulator to direct different wavelengths in sequence to the sample and to process an output of the detector between said wavelengths to yield an extended spectrum.

2. The system of claim 1 in which the optical subsystem includes a grating oriented to disperse said radiation in one plane and a prism configured to disperse said radiation in another plane.

3. The system of claim 2 in which the grating is an Echelle type grating.

4. The system of claim 2 further including a focusing lens between the prism and the pixilated light modulator.

5. The system of claim 2 in which the prism is between the grating and the pixilated light modulator.

6. The system of claim 2 in which the prism is located so electromagnetic radiation passes through the prism before and after reflection from the grating.

7. The system of claim 6 further including a lens between the source and the prism and between the prism and the pixilated light modulator for collimating radiation from the source and focusing radiation from the prism.

8. The system of claim 7 in which said lens is further located between the pixilated light modulator and the sample to focus radiation from the pixilated light monitor onto the sample.

9. The system of claim 1 in which the detector includes an InGaAs and/or a silicon detector.

10. The system of claim 1 in which the source is a visible light source, a near infrared light source, or a mid-infrared light source.

11. The system of claim 1 in which the pixilated light modulator is a digital micro-mirror device with individually operable mirrors in a two dimensional array.

12. The system of claim 1 in which the controller is programmed to control the digital micro-mirror device to direct multiple wavelengths to the sample simultaneously.

13. A method comprising:

dispersing radiation from a source into a plurality of wavelengths;

directing said wavelengths to a pixilated light modulator;

controlling the pixilated light modulator to direct different wavelengths in sequence on to a sample;

detecting said one or more wavelengths using a single element detector sensitive over a wavelength range of approximately 400-2500 nm; and

,

processing an output of the detector between said wavelengths to yield an extended spectrum.

14. The method of claim 13 in which dispersing said radiation includes dispersing radiation in one plane and then directing said dispersed radiation in another plane.

15. The method of claim 13 further including focusing said wavelengths onto the pixilated light modulator.

16. The method of claim 13 further including collimating said radiation from the light source and focusing said wavelengths onto the pixilated light modulator using a single optical component.

17. The method of claim 13 in which dispersing radiation includes dispersing visible, a near infrared, or a mid-infrared light.

18. The method of claim 13 further including controlling the pixilated light modulator to direct multiple wavelengths to the sample simultaneously.

19. A method comprising:

projecting cross-dispersed light onto a micro-mirror array having a plurality of individual mirrors;

activating individual mirrors following a selective sequence of mirror combinations to direct an individual wavelength or individual wavelengths to a sample in sequence;

detecting a signal reflected by the sample of each mirror combination using a single element detector sensitive over a wavelength range of approximately 400-2500 nm; and

,

processing an output of the detector between said wavelengths; and

recovering a complete spectrum by recombining data from signals according to the collection sequence in use.

20. An enhanced spectral range system comprising:

a source of electromagnetic radiation;

a pixilated light modulator configured to direct one or more selected wavelengths to a sample;

a grating between the source and the pixilated light modulator that disperses radiation in one plane;

a prism between the source and the pixilated light modulator that directs said dispersed radiation in a different plane; and

,

a single optical element between the source and the prism that collimates radiation from the source, and between the prism and the pixilated light modulator that focuses radiation from the prism onto the pixilated light modulator.

21. A method comprising:

wavelength-dispersing radiation from a source in one plane and directing said dispersed radiation in another different plane onto a pixilated light modulator;

collimating radiation from the source, and focusing said dispersed radiation onto the pixilated light modulator using a single optical element; and

,

controlling the pixilated light modulator to direct one or more wavelengths onto a sample.

22. A enhanced spectral range system comprising:

a source of electromagnetic radiation;

a lens configured to collimate said radiation;

an optical subsystem including a grating and a prism, said grating configured to disperse said collimated radiation into a plurality of wavelengths in one plane and said prism to redirect said dispersed wavelengths in a different plane, the prism located so that radiation passes through the prism before and after reflection from the grating;

a pixilated light modulator receiving said dispersed radiation wavelengths and configured to direct one or more selective wavelengths on to a sample;

said lens positioned and configured to focus radiation from the prism onto the pixilated light modulation; and

,

a single element detector oriented to receive radiation reflected from the sample.

23. The system of claim 22 in which said lens is further located between the pixilated light modulator and the sample to focus radiation from the pixilated light monitor onto the sample.