Emission and Transmission Optical Spectrometer

• US 20130063714A1
• Filed: 09/10/2012
• Published: 03/14/2013
• Est. Priority Date: 09/08/2011
• Status: Active Grant

• Current Assignee: Thermo Electron Scientific Instruments LLC (Thermo Fisher Scientific Incorporated)
• Original Assignee: Federico Izzia, Michael S. Bradley
• Inventors: IZZIA, Federico, BRADLEY, Michael S.
• Granted Patent: US 9,121,755 B2
• Time in Patent Office: Days
• US Class Current: 356/51
• CPC Class Codes: G01J 3/02 Details
• CPC Class Codes: G01J 3/0202 Mechanical elements; Supports for optical elements
• CPC Class Codes: G01J 3/0235 using means for replacing an element by another, for replacing a filter or a grating
• CPC Class Codes: G01J 3/10 Arrangements of light sources specially adapted for spectrometry or colorimetry
• CPC Class Codes: G01J 3/36 Investigating two or more bands of a spectrum by separate detectors
• CPC Class Codes: G01J 3/44 Raman spectrometry; Scattering spectrometry ; Fluorescence spectrometry
• CPC Class Codes: G01J 3/453 by correlation of the amplitudes
• CPC Class Codes: G01N 21/65 Raman scattering

Abstract

A novel emission and transmission optical spectrometer is introduced herein, which is capable of optically interrogating solid or liquid samples of organic, inorganic or polymeric chemistry, for pharmaceutical research, forensic and liquid analyses, used for identification, purity check, and/or structural study of chemicals. The beneficial aspects of the system are a single sample compartment as confined within the walls of the spectrometer housing, a more compact accessory, and the capability of making both emission (e.g., Raman and Fluorescence) and Infrared (IR, NIR) transmission measurements at designed sample points.

Claims

1. An optical instrument for use in transmission and emission spectroscopy, comprising:

a spectrometer housing having a single sample compartment disposed within the walls of said spectrometer housing;

an accessory coupled to said single sample compartment, said accessory further comprising an excitation source configured to generate emission from a sample coupled to a first sample platform position;

a second sample platform position offset from said first sample platform position so as to be configured for infrared (IR) transmission operation;

an infrared (IR) source of radiation;

an interferometer adapted along a designed optical path so as to modulate either said emission or the light received from said infrared (IR) source of radiation;

a first optical element configured to direct to an emission detector, the emission received along said designed optical path or to direct said infrared (IR) source of light along said designed optical path; and

a second optical element configured to receive directed infrared (IR) light transmitted therethrough a sample coupled to said second platform position and further adapted to direct said infrared (IR) light transmitted therethrough to one or more infrared (IR) detectors.

2. The optical instrument of claim 1, wherein said excitation source configured with said accessory comprises a source configured to provide emission wavelengths from about 630 nm up to about 2400 nm.

3. The optical instrument of claim 2, wherein said excitation source configured with said accessory comprises diode laser configured to provide an emission wavelength at about 1064 nm.

4. The optical instrument of claim 1, wherein said emission induced via interaction of optical light received from said excitation source with said sample coupled to a first sample platform position comprises at least one induced emission selected from:

fluorescence and Raman light.

5. The optical instrument of claim 1, wherein said accessory further comprises a neutral density filter to adjust the power resultant from said excitation source.

6. The optical instrument of claim 1, wherein said accessory further comprises a defocusing lens configured with said excitation source so as to reduce the power density at said sample coupled to said first sample platform.

7. The optical instrument of claim 1, wherein said accessory further comprises a desired bandpass filter to remove amplified stimulated emission and spectral artifacts.

8. The optical instrument of claim 1, wherein said accessory further comprises a white light illumination source configured to enable interrogation of said sample coupled to said first sample platform or alignment of said sample coupled to said first sample platform to enable emission to be directed along said desired optical path.

9. The optical instrument of claim 1, wherein said accessory further comprises one or more edge filters to enable a desired filtered emission to be directed by a predetermined folding optic out of said accessory and along said designed optical path.

10. The optical instrument of claim 1, wherein said one or more infrared (IR) detectors comprise at least one detector selected from:

photodiodes, CCDs, liquid nitrogen cooled CCD cameras, two-dimensional array detectors, avalanche CCD photodetectors, photomultipliers, and a photodiode capable of point by point scanning.

11. The optical instrument of claim 1, wherein said emission detector comprises a Raman detector.

12. The optical instrument of claim 11, wherein said Raman detector comprises a germanium detector.

13. The optical instrument of claim 1, wherein said first and said second optical element further comprises a geared reflector.

14. The optical instrument of claim 13, wherein said geared reflector further comprises an optical reflective surface having at least one surface selected from:

an elliptical surface, a parabolic surface, a toroidal surface, and a flat surface.

15. The optical instrument of claim 1, wherein said optical instrument is configured to measure in the infrared spectra ranges of 150 cm⁻

1 to about 400 cm<sup>−

1</sup> in the far infrared (IR), and from about 400 cm<sup>−

1</sup> to about 4000 cm<sup>−

1</sup> in the mid infrared (IR), and from about 4000 cm<sup>−

1</sup> to about 10000 cm<sup>−

1</sup> in the near infrared with a spectral resolution of at least about 0.125 cm<sup>−

1</sup>.

16. The optical instrument of claim 1, wherein said optical instrument via the aid of said accessory is configured to measure Raman signals in the range from about 50 cm⁻

1 to about 4000 cm<sup>−

1</sup> with a spectral resolution of at least about 0.8 cm<sup>−

1</sup>.