Abstract

An improved Raman gain spectrometer for flame measurements of gas temperature and species concentrations is described. This instrument uses a multiple-pass optical cell to enhance the incident light intensity in the measurement volume. The Raman signal is 83 times larger than from a single pass, and the Raman signal-to-noise ratio (SNR) in room-temperature air of 153 is an improvement over that from a single-pass cell by a factor of 9.3 when the cell is operated with 100 passes and the signal is integrated over 20 laser shots. The SNR improvement with the multipass cell is even higher for flame measurements at atmospheric pressure, because detector readout noise is more significant for single-pass measurements when the gas density is lower. Raman scattering is collected and dispersed in a spectrograph with a transmission grating and recorded with a fast gated CCD array detector to help eliminate flame interferences. The instrument is used to record spontaneous Raman spectra from N2, CO2, O2, and CO in a methane–air flame. Curve fits of the recorded Raman spectra to detailed simulations of nitrogen spectra are used to determine the flame temperature from the shapes of the spectral signatures and from the ratio of the total intensities of the Stokes and anti-Stokes signals. The temperatures measured are in good agreement with radiation-corrected thermocouple measurements for a range of equivalence ratios.

© 2011 Optical Society of America

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  1. D. Herriott, H. Kogelnik, and R. Kompfner, “Off-axis paths in spherical mirror interferometers,” Appl. Opt. 3, 523–526(1964).
    [CrossRef]
  2. J. B. McManus and P. L. Kebabian, “Narrow optical interference fringes for certain setup conditions in multipass absorption cells of the Herriott type,” Appl. Opt. 29, 898–900 (1990).
    [CrossRef] [PubMed]
  3. J. B. McManus, P. L. Kebabian, and M. S. Zahniser, “Astigmatic mirror multipass absorption cells for long-path-length spectroscopy,” Appl. Opt. 34, 3336–3348 (1995).
    [CrossRef] [PubMed]
  4. J. A. Silver, “Simple dense pattern optical multipass cell,” Appl. Opt. 44, 6545–6556 (2005).
    [CrossRef] [PubMed]
  5. B. N. Ganguly, “Hydrocarbon combustion enhancement by applied electric field and plasma kinetics,” Plasma Phys. Control. Fusion 49, B239–B246 (2007).
    [CrossRef]
  6. D. L. Wisman, S. D. Marcum, and B. N. Ganguly, “Electrical control of the thermodiffusive instability in premixed propane–air flames,” Combust. Flame 151, 639–649 (2007).
    [CrossRef]
  7. A. J. Mulac, W. L. Flower, R. A. Hill, and D. P. Aeschliman, “Pulsed spontaneous Raman scattering technique for luminous environments,” Appl. Opt. 17, 2695–2699 (1978).
    [CrossRef] [PubMed]
  8. D. Kaur, A. M. de Souza, J. Wanna, S. A. Hammad, L. Mercorelli, and D. S. Perry, “Multipass cell for molecular beam absorption spectroscopy,” Appl. Opt. 29, 119–124 (1990).
    [CrossRef] [PubMed]
  9. W. R. Trutna and R. L. Byer, “Multiple-pass Raman gain cell,” Appl. Opt. 19, 301–312 (1980).
    [CrossRef] [PubMed]
  10. G. A. Waldherr and H. Lin, “Gain analysis of an optical multipass cell for spectroscopic measurements in luminous environments,” Appl. Opt. 47, 901–907 (2008).
    [CrossRef] [PubMed]
  11. D. A. Long, Raman Spectroscopy (McGraw-Hill, 1977).
  12. W. Knippers, K. van Helvoort, and S. Stolte, “Vibrational overtones of the homonuclear diatomics (N2, O2, D2) observed by the spontaneous Raman effect,” Chem. Phys. Lett. 121, 279–286 (1985).
    [CrossRef]
  13. R. R. Laher and F. R. Gilmore, “Improved fits for the vibrational and rotational constants of many states of nitrogen and oxygen,” J. Phys. Chem. Ref. Data 20, 685–712 (1991).
    [CrossRef]
  14. J. Bendtsen, “The rotational and rotation-vibrational Raman spectra of N142, N14N15 and N152,” J. Raman Spectrosc. 2, 133–145 (1974).
    [CrossRef]
  15. D. Bradley and K. J. Matthews, “Measurement of high gas temperatures with fine wire thermocouples,” J. Mechan. Eng. Science 10, 299–305 (1968).
    [CrossRef]
  16. C. Davisson and J. R. Weeks, Jr., “The relation between the total thermal emissive power of a metal and its electrical resistivity,” J. Opt. Soc. Am. 8, 581–602 (1924).
    [CrossRef]
  17. R. F. Vines, The Platinum Metals and Their Alloys (The International Nickel Company, 1941).
  18. C. Morley, “Gaseq—A chemical equilibrium program for Windows,” http://www.c.morley.dsl.pipex.com/.

2008 (1)

2007 (2)

B. N. Ganguly, “Hydrocarbon combustion enhancement by applied electric field and plasma kinetics,” Plasma Phys. Control. Fusion 49, B239–B246 (2007).
[CrossRef]

D. L. Wisman, S. D. Marcum, and B. N. Ganguly, “Electrical control of the thermodiffusive instability in premixed propane–air flames,” Combust. Flame 151, 639–649 (2007).
[CrossRef]

2005 (1)

1995 (1)

1991 (1)

R. R. Laher and F. R. Gilmore, “Improved fits for the vibrational and rotational constants of many states of nitrogen and oxygen,” J. Phys. Chem. Ref. Data 20, 685–712 (1991).
[CrossRef]

1990 (2)

1985 (1)

W. Knippers, K. van Helvoort, and S. Stolte, “Vibrational overtones of the homonuclear diatomics (N2, O2, D2) observed by the spontaneous Raman effect,” Chem. Phys. Lett. 121, 279–286 (1985).
[CrossRef]

1980 (1)

1978 (1)

1974 (1)

J. Bendtsen, “The rotational and rotation-vibrational Raman spectra of N142, N14N15 and N152,” J. Raman Spectrosc. 2, 133–145 (1974).
[CrossRef]

1968 (1)

D. Bradley and K. J. Matthews, “Measurement of high gas temperatures with fine wire thermocouples,” J. Mechan. Eng. Science 10, 299–305 (1968).
[CrossRef]

1964 (1)

1924 (1)

Aeschliman, D. P.

Bendtsen, J.

J. Bendtsen, “The rotational and rotation-vibrational Raman spectra of N142, N14N15 and N152,” J. Raman Spectrosc. 2, 133–145 (1974).
[CrossRef]

Bradley, D.

D. Bradley and K. J. Matthews, “Measurement of high gas temperatures with fine wire thermocouples,” J. Mechan. Eng. Science 10, 299–305 (1968).
[CrossRef]

Byer, R. L.

Davisson, C.

de Souza, A. M.

Flower, W. L.

Ganguly, B. N.

D. L. Wisman, S. D. Marcum, and B. N. Ganguly, “Electrical control of the thermodiffusive instability in premixed propane–air flames,” Combust. Flame 151, 639–649 (2007).
[CrossRef]

B. N. Ganguly, “Hydrocarbon combustion enhancement by applied electric field and plasma kinetics,” Plasma Phys. Control. Fusion 49, B239–B246 (2007).
[CrossRef]

Gilmore, F. R.

R. R. Laher and F. R. Gilmore, “Improved fits for the vibrational and rotational constants of many states of nitrogen and oxygen,” J. Phys. Chem. Ref. Data 20, 685–712 (1991).
[CrossRef]

Hammad, S. A.

Herriott, D.

Hill, R. A.

Kaur, D.

Kebabian, P. L.

Knippers, W.

W. Knippers, K. van Helvoort, and S. Stolte, “Vibrational overtones of the homonuclear diatomics (N2, O2, D2) observed by the spontaneous Raman effect,” Chem. Phys. Lett. 121, 279–286 (1985).
[CrossRef]

Kogelnik, H.

Kompfner, R.

Laher, R. R.

R. R. Laher and F. R. Gilmore, “Improved fits for the vibrational and rotational constants of many states of nitrogen and oxygen,” J. Phys. Chem. Ref. Data 20, 685–712 (1991).
[CrossRef]

Lin, H.

Long, D. A.

D. A. Long, Raman Spectroscopy (McGraw-Hill, 1977).

Marcum, S. D.

D. L. Wisman, S. D. Marcum, and B. N. Ganguly, “Electrical control of the thermodiffusive instability in premixed propane–air flames,” Combust. Flame 151, 639–649 (2007).
[CrossRef]

Matthews, K. J.

D. Bradley and K. J. Matthews, “Measurement of high gas temperatures with fine wire thermocouples,” J. Mechan. Eng. Science 10, 299–305 (1968).
[CrossRef]

McManus, J. B.

Mercorelli, L.

Morley, C.

C. Morley, “Gaseq—A chemical equilibrium program for Windows,” http://www.c.morley.dsl.pipex.com/.

Mulac, A. J.

Perry, D. S.

Silver, J. A.

Stolte, S.

W. Knippers, K. van Helvoort, and S. Stolte, “Vibrational overtones of the homonuclear diatomics (N2, O2, D2) observed by the spontaneous Raman effect,” Chem. Phys. Lett. 121, 279–286 (1985).
[CrossRef]

Trutna, W. R.

van Helvoort, K.

W. Knippers, K. van Helvoort, and S. Stolte, “Vibrational overtones of the homonuclear diatomics (N2, O2, D2) observed by the spontaneous Raman effect,” Chem. Phys. Lett. 121, 279–286 (1985).
[CrossRef]

Vines, R. F.

R. F. Vines, The Platinum Metals and Their Alloys (The International Nickel Company, 1941).

Waldherr, G. A.

Wanna, J.

Weeks, J. R.

Wisman, D. L.

D. L. Wisman, S. D. Marcum, and B. N. Ganguly, “Electrical control of the thermodiffusive instability in premixed propane–air flames,” Combust. Flame 151, 639–649 (2007).
[CrossRef]

Zahniser, M. S.

Appl. Opt. (8)

Chem. Phys. Lett. (1)

W. Knippers, K. van Helvoort, and S. Stolte, “Vibrational overtones of the homonuclear diatomics (N2, O2, D2) observed by the spontaneous Raman effect,” Chem. Phys. Lett. 121, 279–286 (1985).
[CrossRef]

Combust. Flame (1)

D. L. Wisman, S. D. Marcum, and B. N. Ganguly, “Electrical control of the thermodiffusive instability in premixed propane–air flames,” Combust. Flame 151, 639–649 (2007).
[CrossRef]

J. Mechan. Eng. Science (1)

D. Bradley and K. J. Matthews, “Measurement of high gas temperatures with fine wire thermocouples,” J. Mechan. Eng. Science 10, 299–305 (1968).
[CrossRef]

J. Opt. Soc. Am. (1)

J. Phys. Chem. Ref. Data (1)

R. R. Laher and F. R. Gilmore, “Improved fits for the vibrational and rotational constants of many states of nitrogen and oxygen,” J. Phys. Chem. Ref. Data 20, 685–712 (1991).
[CrossRef]

J. Raman Spectrosc. (1)

J. Bendtsen, “The rotational and rotation-vibrational Raman spectra of N142, N14N15 and N152,” J. Raman Spectrosc. 2, 133–145 (1974).
[CrossRef]

Plasma Phys. Control. Fusion (1)

B. N. Ganguly, “Hydrocarbon combustion enhancement by applied electric field and plasma kinetics,” Plasma Phys. Control. Fusion 49, B239–B246 (2007).
[CrossRef]

Other (3)

R. F. Vines, The Platinum Metals and Their Alloys (The International Nickel Company, 1941).

C. Morley, “Gaseq—A chemical equilibrium program for Windows,” http://www.c.morley.dsl.pipex.com/.

D. A. Long, Raman Spectroscopy (McGraw-Hill, 1977).

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Figures (16)

Fig. 1
Fig. 1

Schematic layout of multiple-pass Raman spectrometer: D, beam dump; M, mirror; PR, polarization rotator; ML, mode-matching lens pair; and TL, image transfer camera lenses.

Fig. 2
Fig. 2

Plot of relative intensity of exiting beam versus distance after N passes of the cell for 99.7% reflective mirrors. The different orders of K = 2 , 4 , and 6 are shown for up to 250 passes.

Fig. 3
Fig. 3

Plot of multiple-pass cell beam pattern diameter in cell center (Raman imaging volume) as a function of mirror separation in millimeters and in reduced units ( d / 4 f ). Circular markers denote diameters for 100, 120, and 150 passes.

Fig. 4
Fig. 4

Photograph of spot pattern on rear mirror of cell for N = 122 . Some spot numbers on this mirror are noted.

Fig. 5
Fig. 5

Time dependence of laser intensity in Raman imaging volume for 12 ns pulse as a function of N with a reflectivity of 99.7%. The dashed line shows the envelope for N = 120 .

Fig. 6
Fig. 6

Raman scattering signal measured for the N 2 Stokes signal in room-temperature air for a single pass and for 100 passes through the Raman cell.

Fig. 7
Fig. 7

Plot of expected signal gain versus number of passes for Raman multiple-pass cell assuming mirror reflectivity of 99.7%. The diamond symbol shows the measured signal gain for N = 100 .

Fig. 8
Fig. 8

Comparison of the (a) single-pass and (b) 100-pass signals in the region of the N 2 Stokes Q branch in room-temperature air integrated over the same time intervals: dashed curve, long time ( 3 × 10 4 pulses); solid curve, short time (20 pulses). Note the difference in scales between (a) and (b).

Fig. 9
Fig. 9

Comparison of the (a) single-pass ( SNR = 16.4 ) and (b) 100 pass ( SNR = 153.4 ) signal and noise traces for the N 2 Stokes Q branch in room-temperature air integrated over the same time intervals: dashed curve, long time ( 3 × 10 4 pulses) (virtually noise free); solid curve, short time (20 pulses). The SNR improves by a factor of 9.3 for the 100-pass configuration.

Fig. 10
Fig. 10

Comparison of the (a) single-pass ( SNR = 2.47 ) and (b) 100-pass ( SNR = 134.9 ) signal and noise traces for the N 2 Stokes Q branch in a flame integrated over the same time intervals: dashed curve, long integration time ( 10 5 pulses) (nearly noise free); solid curve, shorter integration time ( 10 3 pulses). The SNR improves by a factor of 54 for the 100-pass configuration.

Fig. 11
Fig. 11

Line shape from Xe calibration lamp used to determine spectral resolution of spectrometer. Data (circle points) are fit well by the Voigt profile (solid curve), with small residuals (dashed curve).

Fig. 12
Fig. 12

Calibration factors in the (a) blue and (b) red obtained from the recorded blackbody spectrum. The curve fits were used to convert the Raman scattered photon counts to the intensities.

Fig. 13
Fig. 13

Raman spectra in postflame gases of (a) lean ( ϕ = 0.66 ), (b) near-stoichiometric ( ϕ = 0.94 ), and (c) rich ( ϕ = 1.24 ) methane–air flames over the flat flame burner.

Fig. 14
Fig. 14

Room-temperature Stokes spectrum of N 2 and best- fit simulation using instrumental broadening parameters determined from these data.

Fig. 15
Fig. 15

Curve fit to N 2 Raman signal obtained in the 100-pass configuration when ( ϕ = 0.94 ). (a) Stokes and (b) anti-Stokes. The curve fits were used to determine total Stokes and anti-Stokes signal intensities.

Fig. 16
Fig. 16

Temperature of the flame from Raman thermometry and radiation corrected thermocouple measurements. The thermocouple measurements have been slightly displaced in ϕ for clarity.

Tables (1)

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Table 1 Design Parameters for Multiple-Pass Raman Cell

Equations (9)

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I ( λ ) = G T [ υ + 1 ] [ υ 0 υ k ( υ , J ) ] 4 υ ( υ ) ϕ x g s ( J ) [ 2 J + 1 ] e h c E υ ( υ ) k T e h c E J ( υ , J ) k T Q ( T ) L ( λ ; λ k ( v , J ) , y , Δ λ D ) .
ϕ J J 2 = 7 45 ( γ ) 2 b J 2 , J = 7 45 ( γ ) 2 3 J ( J 1 ) 2 ( 2 J + 1 ) ( 2 J 1 ) ,
ϕ J J = ( a ) 2 + 7 45 ( γ ) 2 b J , J = ( a ) 2 + 7 45 ( γ ) 2 J ( J + 1 ) ( 2 J 1 ) ( 2 J + 3 ) ,
ϕ J J + 2 = 7 45 ( γ ) 2 b J + 2 , J = 7 45 ( γ ) 2 3 ( J + 1 ) ( J + 2 ) 2 ( 2 J + 1 ) ( 2 J + 3 ) .
E v ( v ) = ω e ( v + 1 2 ) ω e x e ( v + 1 2 ) 2 + ω e y e ( v + 1 2 ) 3 + ω e z e ( v + 1 2 ) 4 ,
E J ( v , J ) = [ B e α e ( v + 1 2 ) + γ e ( v + 1 2 ) 2 ] J ( J + 1 ) D J 2 ( J + 1 ) 2 .
L ( λ ; λ k ( v , J ) , y , Δ λ D ) = 1 π Δ λ D V ( x ; y ) .
y = Δ λ C Δ λ D ,
x = λ λ k Δ λ D ,

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