US5751415A — Raman spectroscopy apparatus and method for conti…

Claim 1

Independent Claim 268 words

A method for continuously analyzing the composition of a fluid stream using Raman spectroscopy comprising the steps of: (a) introducing the fluid stream into a tubular Raman enhancement cell comprising: a fluid stream inlet and a fluid stream outlet located adjacent the ends of the enhancement cell for continuous fluid flow through the enhancement cell; an optical connector located at one end of the enhancement cell for connecting a bundle of optical fibers to the enhancement cell, wherein said bundle of optical fibers includes at least one excitation optical fiber and one or more collection optical fibers; and a transparent fluid barrier located between the bundle of optical fibers and the enhancement cell; (b) introducing light having an excitation wavelength into the Raman enhancement cell through the excitation optical fiber; (c) collecting backscattered Raman light from the enhancement cell with the one or more collection optical fibers; (d) measuring the backscattered light with a Raman spectrometer comprising: a linear array of the one or more collection optical fibers for generating an optical signal of the scattered light from the enhancement cell; a filter for rejecting portions of the optical signal having the excitation wavelength; a volume holographic transmission grating to disperse the light; a transmissive aberration correction element for correcting optical aberrations introduced into optical signal by the volume holographic transmission grating, said aberration correction element comprising at least one optically transparent wedge or prism; and a charge coupled device array for converting the optical signal into a corresponding electronic signal; and (e) converting the electronic signal into a representation of the chemical analysis of the fluid stream.

Claim 2

Independent Claim 268 words

A method for continuously analyzing the composition of a fluid stream using Raman spectroscopy comprising the steps of: (a) introducing the fluid stream into a tubular Raman enhancement cell comprising: a fluid stream inlet and a fluid stream outlet located adjacent the ends of the enhancement cell for continuous fluid flow through the enhancement cell; an optical connector located at one end of the enhancement cell for connecting a bundle of optical fibers to the enhancement cell, wherein said bundle of optical fibers includes at least one excitation optical fiber and one or more collection optical fibers; and a transparent fluid barrier located between the bundle of optical fibers and the enhancement cell; (b) introducing light having an excitation wavelength into the Raman enhancement cell through the excitation optical fiber; (c) collecting backscattered Raman light from the enhancement cell with the one or more collection optical fibers; (d) measuring the backscattered light with a Raman spectrometer comprising: a linear array of the one or more collection optical fibers for generating an optical signal of the scattered light from the enhancement cell; a filter for rejecting portions of the optical signal having the excitation wavelength; a volume holographic transmission grating to disperse the light; a transmissive aberration correction element for correcting optical aberrations introduced into optical signal by the volume holographic transmission grating, said aberration correction element comprising at least one optically transparent wedge or prism; and a charge coupled device array for converting the optical signal into a corresponding electronic signal; and (e) converting the electronic signal into a representation of the chemical analysis of the fluid stream.

Claim 3

Dependent Claim 45 words

A method as defined in claim 1, wherein the backscattered light is measured with a Raman spectrometer comprising a plurality of optical lenses for receiving and conveying the optical signal from the linear array of the collection optical fibers to the charge coupled device array.

Claim 4

Dependent Claim 21 words

A method as defined in claim 1, wherein the fluid stream introduced into a tubular Raman enhancement cell contains petroleum products.

Claim 5

Dependent Claim 25 words

A method as defined in claim 1, further comprising the step of positioning the Raman enhancement cell at a remote location from the Raman spectrometer.

Claim 6

Dependent Claim 33 words

A method as defined in claim 1, wherein the tubular Raman enhancement cell is lined with a material having an index of refraction less than the index of refraction of the fluid stream.

Claim 7

Dependent Claim 19 words

A method as defined in claim 5, wherein the tubular Raman enhancement cell is lined with a fluorinated polymer.

Claim 8

Dependent Claim 25 words

A method as defined in claim 6, wherein the fluorinated polymer is selected from the group consisting of polytetrafluoroethylene (PTFE), FEP, PFA, AF and Tefzel.

Claim 9

Dependent Claim 41 words

A method as defined in claim 5, wherein the fluid stream introduced into a tubular Raman enhancement cell contains petroleum products and wherein the tubular Raman enhancement cell is lined with a polymer having an index of refraction less than 1.4.

Claim 10

Dependent Claim 43 words

A method as defined in claim 5, wherein the fluid stream introduced into a tubular Raman enhancement cell contains aqueous or biological solutions and wherein the tubular Raman enhancement cell is lined with a polymer having an index of refraction less than 1.33.

Claim 11

Dependent Claim 27 words

A method as defined in claim 1, wherein the tubular Raman enhancement cell has a length in the range from about 0.1 m to about 4 m.

Claim 12

Dependent Claim 25 words

A method as defined in claim 1, wherein the tubular Raman enhancement cell has a diameter in the range from about 0.005 to 0.2 inches.

Claim 13

Dependent Claim 32 words

A method as defined in claim 1, further comprising the step of aligning the tubular Raman enhancement cell in a linear orientation between the fluid stream inlet and the fluid stream outlet.

Claim 14

Dependent Claim 32 words

A method as defined in claim 1, further comprising the step of aligning the tubular Raman enhancement cell in a curved orientation between the fluid stream inlet and the fluid stream outlet.

Claim 15

Dependent Claim 19 words

A method as defined in claim 1, wherein the aberration correction element comprises two optically transparent wedges or prisms.

Claim 16

Dependent Claim 21 words

A method as defined in claim 1, wherein the bundle of optical fibers includes from 20 to 50 collection optical fibers.

Claim 17

Dependent Claim 21 words

A method as defined in claim 1, wherein the backscattered light is measured with a Raman spectrometer comprising an optical slit.

Claim 18

Dependent Claim 22 words

A method as defined in claim 16, wherein the optical slit has dimensions comparable to the linear array of collection optical fibers.

Claim 19

Dependent Claim 23 words

A method as defined in claim 16, wherein the optical slit has a width in the range from 10 microns to 150 microns.

Claim 20

Dependent Claim 34 words

A method as defined in claim 1, wherein the transparent fluid barrier includes a layer of index matching fluid to maintain optimum optical coupling between the bundle of optical fibers and the fluid barrier.

Claim 21

Independent Claim 228 words

An apparatus for analyzing the composition of a fluid stream using Raman spectroscopy comprising: a laser source for producing light having an excitation wavelength; a bundle of optical fibers comprising one or more excitation optical fibers and a plurality of collection optical fibers; a tubular Raman enhancement cell comprising: a fluid stream inlet and a fluid stream outlet located adjacent the ends of the enhancement cell for continuous fluid flow through the enhancement cell; an optical connector located at one end of the enhancement cell for connecting the bundle of optical fibers to the enhancement cell; and a transparent fluid barrier located between the bundle of optical fibers and the enhancement cell; a Raman spectrometer comprising: a linear array of the collection optical fibers for generating a linear optical signal of the scattered light from the enhancement cell; a filter for rejecting portions of the optical signal having the excitation wavelength; a volume holographic transmission grating to disperse the signal and a transmissive aberration correction element for correcting optical aberrations introduced into optical signal by the volume holographic transmission grating, said aberration correction element comprising at least one optically transparent wedge or prism; and a charge coupled device array for converting the optical signal into a corresponding electronic signal; and a computer for converting the electronic signal into a representation of the chemical analysis of the fluid stream.

Claim 22

Independent Claim 228 words

An apparatus for analyzing the composition of a fluid stream using Raman spectroscopy comprising: a laser source for producing light having an excitation wavelength; a bundle of optical fibers comprising one or more excitation optical fibers and a plurality of collection optical fibers; a tubular Raman enhancement cell comprising: a fluid stream inlet and a fluid stream outlet located adjacent the ends of the enhancement cell for continuous fluid flow through the enhancement cell; an optical connector located at one end of the enhancement cell for connecting the bundle of optical fibers to the enhancement cell; and a transparent fluid barrier located between the bundle of optical fibers and the enhancement cell; a Raman spectrometer comprising: a linear array of the collection optical fibers for generating a linear optical signal of the scattered light from the enhancement cell; a filter for rejecting portions of the optical signal having the excitation wavelength; a volume holographic transmission grating to disperse the signal and a transmissive aberration correction element for correcting optical aberrations introduced into optical signal by the volume holographic transmission grating, said aberration correction element comprising at least one optically transparent wedge or prism; and a charge coupled device array for converting the optical signal into a corresponding electronic signal; and a computer for converting the electronic signal into a representation of the chemical analysis of the fluid stream.

Claim 23

Dependent Claim 40 words

An apparatus as defined in claim 20, wherein the Raman spectrometer further comprises a plurality of optical lenses for receiving and conveying the optical signal from the linear array of the collection optical fibers to the charge coupled device array.

Claim 24

Dependent Claim 33 words

An apparatus as defined in claim 20, wherein the tubular Raman enhancement cell is lined with a material having an index of refraction less than the index of refraction of the fluid stream.

Claim 25

Dependent Claim 19 words

An apparatus as defined in claim 20, wherein the tubular Raman enhancement cell is lined with a fluorinated polymer.

Claim 26

Dependent Claim 25 words

An apparatus as defined in claim 23, wherein the fluorinated polymer is selected from the group consisting of polytetrafluoroethylene (PTFE), FEP, PFA, AF and Tefzel.

Claim 27

Dependent Claim 33 words

An apparatus as defined in claim 20, wherein the fluid stream contains petroleum products and the tubular Raman enhancement cell is lined with a polymer having an index of refraction less than 1.4.

Claim 28

Dependent Claim 35 words

An apparatus as defined in claim 20, wherein the fluid stream contains aqueous or biological solutions and the tubular Raman enhancement cell is lined with a polymer having an index of refraction less than 1.33.

Claim 29

Dependent Claim 27 words

An apparatus as defined in claim 20, wherein the tubular Raman enhancement cell has a length in the range from about 0.1 m to about 4 m.

Claim 30

Dependent Claim 25 words

An apparatus as defined in claim 20, wherein the tubular Raman enhancement cell has a diameter in the range from about 0.005 to 0.2 inches.

Claim 31

Dependent Claim 19 words

An apparatus as defined in claim 20, wherein the tubular Raman enhancement cell is constructed of a flexible material.

Claim 32

Dependent Claim 19 words

An apparatus as defined in claim 20, wherein the tubular Raman enhancement cell is constructed of a rigid material.

Claim 33

Dependent Claim 19 words

An apparatus as defined in claim 20, wherein the aberration correction element comprises two optically transparent wedges or prisms.

Claim 34

Dependent Claim 22 words

An apparatus as defined in claim 31, wherein the volume holographic transmission grating is in physical contact with the aberration correction element.

Claim 35

Dependent Claim 24 words

An apparatus as defined in claim 20, wherein the aberration correction element and optical lenses are coated with anti-reflection coatings to minimize light losses.

Claim 36

Dependent Claim 21 words

An apparatus as defined in claim 20, wherein the bundle of optical fibers includes from 20 to 50 collection optical fibers.

Claim 37

Dependent Claim 16 words

An apparatus as defined in claim 20, wherein the Raman spectrometer further comprises an optical slit.

Claim 38

Dependent Claim 22 words

An apparatus as defined in claim 35, wherein the optical slit has dimensions comparable to the linear array of collection optical fibers.

Claim 39

Dependent Claim 23 words

An apparatus as defined in claim 35, wherein the optical slit has a width in the range from 10 microns to 150 microns.

Claim 40

Dependent Claim 15 words

An apparatus as defined in claim 20, wherein the transparent fluid barrier includes a lens.

Claim 41

Dependent Claim 16 words

An apparatus as defined in claim 20, wherein the transparent fluid barrier includes an optical window.

Claim 42

Dependent Claim 34 words

An apparatus as defined in claim 20, wherein the transparent fluid barrier includes a layer of index matching fluid to maintain optimum optical coupling between the bundle of optical fibers and the fluid barrier.

Claim 43

Independent Claim 146 words

An apparatus for analyzing the composition of a sample using Raman spectroscopy comprising: a laser source for producing light having an excitation wavelength, wherein the light is directed into a sample and wherein a Raman signal exits the sample as an optical signal; a Raman spectrometer configured to receive the optical signal comprising: a filter for rejecting portions of the optical signal having the excitation wavelength; an optical slit; a volume holographic transmission grating to disperse the optical signal and a transmissive aberration correction element for correcting optical aberrations introduced into optical signal by the volume holographic transmission grating, said aberration correction element comprising at least one optically transparent wedge or prism; and a charge coupled device array for converting the optical signal into a corresponding electronic signal; and a computer for converting the electronic signal into a representation of the chemical analysis of the sample.

Claim 44

Independent Claim 146 words

An apparatus for analyzing the composition of a sample using Raman spectroscopy comprising: a laser source for producing light having an excitation wavelength, wherein the light is directed into a sample and wherein a Raman signal exits the sample as an optical signal; a Raman spectrometer configured to receive the optical signal comprising: a filter for rejecting portions of the optical signal having the excitation wavelength; an optical slit; a volume holographic transmission grating to disperse the optical signal and a transmissive aberration correction element for correcting optical aberrations introduced into optical signal by the volume holographic transmission grating, said aberration correction element comprising at least one optically transparent wedge or prism; and a charge coupled device array for converting the optical signal into a corresponding electronic signal; and a computer for converting the electronic signal into a representation of the chemical analysis of the sample.

Claim 45

Dependent Claim 31 words

An apparatus as defined in claim 41, wherein the Raman spectrometer further comprises a plurality of optical lenses for receiving and conveying the optical signal to the charge coupled device array.

Claim 46

Dependent Claim 19 words

An apparatus as defined in claim 41, wherein the aberration correction element comprises two optically transparent wedges or prisms.

Claim 47

Dependent Claim 22 words

An apparatus as defined in claim 43, wherein the volume holographic transmission grating is in physical contact with the aberration correction element.

Claim 48

Dependent Claim 24 words

An apparatus as defined in claim 41, wherein the aberration correction element and optical lenses are coated with anti-reflection coatings to minimize light losses.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	2001-05-11	2001-11-10	2002-05-12	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2005-05-11	2005-11-10	2006-05-12	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2009-05-11	2009-11-10	2010-05-12	$7700.00	Window Closed / Lapsed

Raman spectroscopy apparatus and method for continuous chemical analysis of fluid streams

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