Abstract

A versatile mid-infrared hyperspectral imaging system is demonstrated by combining a broadly tunable external cavity quantum cascade laser and a microbolometer focal plane array. The tunable midinfrared laser provided high brightness illumination over a tuning range from 985 cm-1 to 1075 cm-1 (9.30–10.15 µm). Hypercubes containing images at 300 wavelengths separated by 0.3 cm-1 were obtained in 12 s. High spectral resolution chemical imaging of methanol vapor was demonstrated for both static and dynamic systems. The system was also used to image and characterize multiple component liquid and solid samples.

© 2008 Optical Society of America

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    [CrossRef] [PubMed]
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    [CrossRef] [PubMed]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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    [CrossRef]
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  25. P. G. Lucey, T. J. Williams, J. L. Hinrichs, M. E. Winter, D. Steutel, and E. M. Winter, "Three years of operation of AHI: the University of Hawaii's Airborne Hyperspectral Imager," in SPIE Infrared Technology and Applications XXVII 112-120 (2001).
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    [CrossRef]
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    [CrossRef]
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2007 (5)

X. J. Wang, J. Y. Fan, T. Tanbun-Ek, and F. S. Choa, "Low threshold quantum-cascade lasers of room temperature continuous-wave operation grown by metal-organic chemical-vapor deposition," Appl. Phys. Lett. 90, 211103 (2007).
[CrossRef]

A. Evans, S. R. Darvish, S. Slivken, J. Nguyen, Y. Bai, and M. Razeghi, "Buried heterostructure quantum cascade lasers with high continuous-wave wall plug efficiency," Appl. Phys. Lett. 91, 071101 (2007).
[CrossRef]

M. C. Phillips, T. L. Myers, M. D. Wojcik, B. D. Cannon, M. S. Taubman, and D. C. Scott, "Measurement of broad absorption features using a tunable external cavity quantum cascade laser," in SPIE Infrared, Mid-IR, and Terahertz Technologies for Health and the Environment II676003-676011 (2007).

M. C. Phillips, T. L. Myers, M. D. Wojcik, and B. D. Cannon, "External cavity quantum cascade laser for quartz tuning fork photoacoustic spectroscopy of broad absorption features," Opt. Lett. 32, 1177-1179 (2007).
[CrossRef] [PubMed]

R. Lewicki, G. Wysocki, A. A. Kosterev, and F. K. Tittel, "QEPAS based detection of broadband absorbing molecules using a widely tunable, cw quantum cascade laser at 8.4 mu m," Opt. Express 15, 7357-7366 (2007).
[CrossRef] [PubMed]

2006 (6)

L. Diehl, D. Bour, S. Corzine, J. Zhu, G. Hofler, M. Loncar, M. Troccoli, and F. Capasso, "High-power quantum cascade lasers grown by low-pressure metal organic vapor-phase epitaxy operating in continuous wave above 400 K," Appl. Phys. Lett. 88, 201115 (2006).
[CrossRef]

A. Wittmann, M. Giovannini, J. Faist, L. Hvozdara, S. Blaser, D. Hofstetter, and E. Gini, "Room temperature, continuous wave operation of distributed feedback quantum cascade lasers with widely spaced operation frequencies," Appl. Phys. Lett. 89, 141116 (2006).
[CrossRef]

R. Maulini, A. Mohan, M. Giovannini, J. Faist, and E. Gini, "External cavity quantum-cascade laser tunable from 8.2 to 10.4 mu m using a gain element with a heterogeneous cascade," Appl. Phys. Lett. 88, 201113 (2006).
[CrossRef]

M. Pushkarsky, A. Tsekoun, I. G. Dunayevskiy, R. Go, and C. K. N. Patel, "Sub-parts-per-billion level detection of NO2 using room-temperature quantum cascade lasers," Proc. Natl. Acad. Sci. USA 103, 10846-10849 (2006).
[CrossRef] [PubMed]

A. W. M. Lee, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Real-time imaging using a 4.3-THz quantum cascade laser and a 320 x 240 microbolometer focal-plane array," IEEE Photon. Technol. Lett. 18, 1415-1417 (2006).
[CrossRef]

L. M. Miller and P. Dumas, "Chemical imaging of biological tissue with synchrotron infrared light," Biochem. Biphys. Acta 1758, 846-857 (2006).
[CrossRef]

2005 (3)

I. W. Levin and R. Bhargava, "Fourier transform infrared vibrational spectroscopic imaging: Integrating microscopy and molecular recognition," Annu. Rev. Phys. Chem. 56, 429-474 (2005).
[CrossRef] [PubMed]

G. Wysocki, R. F. Curl, F. K. Tittel, R. Maulini, J. M. Bulliard, and J. Faist, "Widely tunable mode-hop free external cavity quantum cascade laser for high resolution spectroscopic applications," Appl. Phys. B 81, 769-777 (2005).
[CrossRef]

Y. Wang, Y. Wang, and H. Q. Le, "Multi-spectral mid-infrared laser stand-off imaging," Opt. Express 13, 6572-6586 (2005).
[CrossRef] [PubMed]

2004 (4)

2003 (1)

2002 (2)

G. Totschnig, F. Winter, V. Pustogov, J. Faist, and A. Muller, "Mid-infrared external-cavity quantum-cascade laser," Opt. Lett. 27, 1788-1790 (2002).
[CrossRef]

M. Beck, D. Hofstetter, T. Aellen, J. Faist, U. Oesterle, M. Ilegems, E. Gini, and H. Melchior, "Continuous wave operation of a mid-infrared semiconductor laser at room temperature," Science 295, 301-305 (2002).
[CrossRef] [PubMed]

2001 (2)

C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, "Recent progress in quantum cascade lasers and applications," Rep. Prog. Phys. 64, 1533-1601 (2001).
[CrossRef]

G. P. Luo, C. Peng, H. Q. Le, S. S. Pei, W. Y. Hwang, B. Ishaug, J. Um, J. N. Baillargeon, and C. H. Lin, "Grating-tuned external-cavity quantum-cascade semiconductor lasers," Appl. Phys. Lett. 78, 2834-2836 (2001).
[CrossRef]

2000 (1)

1999 (1)

T. J. Cudahy, L. B. Whitbourn, P. M. Conner, P. Mason, and R. N. Phillips, "Mapping surface mineralogy and scattering behavior using backscattered reflectance from a hyperspectral midinfrared airborne CO2 laser system (MIRACO(2)LAS)," IEEE Trans. Geosci. Remote Sens. 37, 2019-2034 (1999).
[CrossRef]

1995 (2)

J. A. Reffner, P. A. Martoglio, and G. P. Williams, "Fourier-Transform Infrared Microscopic Analysis with Synchrotron-Radiation - the Microscope Optics and System Performance," Rev. Sci. Instrum. 66, 1298-1302 (1995).
[CrossRef]

E. N. Lewis, P. J. Treado, R. C. Reeder, G. M. Story, A. E. Dowrey, C. Marcott, and I. W. Levin, "Fourier-Transform Spectroscopic Imaging Using an Infrared Focal-Plane Array Detector," Anal. Chem. 67, 3377-3381 (1995).
[CrossRef] [PubMed]

1994 (1)

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, "Quantum Cascade Laser," Science 264, 553-556 (1994).
[CrossRef] [PubMed]

Anal. Chem. (1)

E. N. Lewis, P. J. Treado, R. C. Reeder, G. M. Story, A. E. Dowrey, C. Marcott, and I. W. Levin, "Fourier-Transform Spectroscopic Imaging Using an Infrared Focal-Plane Array Detector," Anal. Chem. 67, 3377-3381 (1995).
[CrossRef] [PubMed]

Annu. Rev. Phys. Chem. (1)

I. W. Levin and R. Bhargava, "Fourier transform infrared vibrational spectroscopic imaging: Integrating microscopy and molecular recognition," Annu. Rev. Phys. Chem. 56, 429-474 (2005).
[CrossRef] [PubMed]

Appl. Phys. B (1)

G. Wysocki, R. F. Curl, F. K. Tittel, R. Maulini, J. M. Bulliard, and J. Faist, "Widely tunable mode-hop free external cavity quantum cascade laser for high resolution spectroscopic applications," Appl. Phys. B 81, 769-777 (2005).
[CrossRef]

Appl. Phys. Lett. (7)

A. Evans, J. S. Yu, J. David, L. Doris, K. Mi, S. Slivken, and M. Razeghi, "High-temperature, high-power, continuous-wave operation of buried heterostructure quantum-cascade lasers," Appl. Phys. Lett. 84, 314-316 (2004).
[CrossRef]

X. J. Wang, J. Y. Fan, T. Tanbun-Ek, and F. S. Choa, "Low threshold quantum-cascade lasers of room temperature continuous-wave operation grown by metal-organic chemical-vapor deposition," Appl. Phys. Lett. 90, 211103 (2007).
[CrossRef]

A. Evans, S. R. Darvish, S. Slivken, J. Nguyen, Y. Bai, and M. Razeghi, "Buried heterostructure quantum cascade lasers with high continuous-wave wall plug efficiency," Appl. Phys. Lett. 91, 071101 (2007).
[CrossRef]

L. Diehl, D. Bour, S. Corzine, J. Zhu, G. Hofler, M. Loncar, M. Troccoli, and F. Capasso, "High-power quantum cascade lasers grown by low-pressure metal organic vapor-phase epitaxy operating in continuous wave above 400 K," Appl. Phys. Lett. 88, 201115 (2006).
[CrossRef]

A. Wittmann, M. Giovannini, J. Faist, L. Hvozdara, S. Blaser, D. Hofstetter, and E. Gini, "Room temperature, continuous wave operation of distributed feedback quantum cascade lasers with widely spaced operation frequencies," Appl. Phys. Lett. 89, 141116 (2006).
[CrossRef]

G. P. Luo, C. Peng, H. Q. Le, S. S. Pei, W. Y. Hwang, B. Ishaug, J. Um, J. N. Baillargeon, and C. H. Lin, "Grating-tuned external-cavity quantum-cascade semiconductor lasers," Appl. Phys. Lett. 78, 2834-2836 (2001).
[CrossRef]

R. Maulini, A. Mohan, M. Giovannini, J. Faist, and E. Gini, "External cavity quantum-cascade laser tunable from 8.2 to 10.4 mu m using a gain element with a heterogeneous cascade," Appl. Phys. Lett. 88, 201113 (2006).
[CrossRef]

Appl. Spectrosc. (3)

Biochem. Biphys. Acta (1)

L. M. Miller and P. Dumas, "Chemical imaging of biological tissue with synchrotron infrared light," Biochem. Biphys. Acta 1758, 846-857 (2006).
[CrossRef]

IEEE Photon. Technol. Lett. (1)

A. W. M. Lee, B. S. Williams, S. Kumar, Q. Hu, and J. L. Reno, "Real-time imaging using a 4.3-THz quantum cascade laser and a 320 x 240 microbolometer focal-plane array," IEEE Photon. Technol. Lett. 18, 1415-1417 (2006).
[CrossRef]

IEEE Trans. Geosci. Remote Sens. (1)

T. J. Cudahy, L. B. Whitbourn, P. M. Conner, P. Mason, and R. N. Phillips, "Mapping surface mineralogy and scattering behavior using backscattered reflectance from a hyperspectral midinfrared airborne CO2 laser system (MIRACO(2)LAS)," IEEE Trans. Geosci. Remote Sens. 37, 2019-2034 (1999).
[CrossRef]

Mid-IR, and Terahertz Technologies for Health and the Environment (1)

M. C. Phillips, T. L. Myers, M. D. Wojcik, B. D. Cannon, M. S. Taubman, and D. C. Scott, "Measurement of broad absorption features using a tunable external cavity quantum cascade laser," in SPIE Infrared, Mid-IR, and Terahertz Technologies for Health and the Environment II676003-676011 (2007).

Opt. Express (4)

Opt. Lett. (2)

Proc. Natl. Acad. Sci. USA (1)

M. Pushkarsky, A. Tsekoun, I. G. Dunayevskiy, R. Go, and C. K. N. Patel, "Sub-parts-per-billion level detection of NO2 using room-temperature quantum cascade lasers," Proc. Natl. Acad. Sci. USA 103, 10846-10849 (2006).
[CrossRef] [PubMed]

Rep. Prog. Phys. (1)

C. Gmachl, F. Capasso, D. L. Sivco, and A. Y. Cho, "Recent progress in quantum cascade lasers and applications," Rep. Prog. Phys. 64, 1533-1601 (2001).
[CrossRef]

Rev. Sci. Instrum. (1)

J. A. Reffner, P. A. Martoglio, and G. P. Williams, "Fourier-Transform Infrared Microscopic Analysis with Synchrotron-Radiation - the Microscope Optics and System Performance," Rev. Sci. Instrum. 66, 1298-1302 (1995).
[CrossRef]

Science (2)

J. Faist, F. Capasso, D. L. Sivco, C. Sirtori, A. L. Hutchinson, and A. Y. Cho, "Quantum Cascade Laser," Science 264, 553-556 (1994).
[CrossRef] [PubMed]

M. Beck, D. Hofstetter, T. Aellen, J. Faist, U. Oesterle, M. Ilegems, E. Gini, and H. Melchior, "Continuous wave operation of a mid-infrared semiconductor laser at room temperature," Science 295, 301-305 (2002).
[CrossRef] [PubMed]

Other (3)

J. A. Hackwell, D. W. Warren, R. P. Bongiovi, S. J. Hansel, T. L. Hayhurst, D. J. Mabry, M. G. Sivjee, and J. W. Skinner, "LWIR/MWIR imaging hyperspectral sensor for airborne and ground-based remote sensing," in SPIE Imaging Spectrometry II 102-107 (1996).

P. G. Lucey, T. J. Williams, J. L. Hinrichs, M. E. Winter, D. Steutel, and E. M. Winter, "Three years of operation of AHI: the University of Hawaii's Airborne Hyperspectral Imager," in SPIE Infrared Technology and Applications XXVII 112-120 (2001).

R. G. Messerschmidt and M. A. Harthcock, eds., Infrared microspectroscopy. Theory and applications (Marcel Dekker, New York, 1988).

Supplementary Material (1)

» Media 1: MOV (1812 KB)     

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Figures (5)

Fig. 1.
Fig. 1.

Active hyperspectral imaging setup using the tunable external cavity quantum cascade laser (ECQCL). (a) The ECQCL beam was expanded by an f=50 mm lens to provide illumination of the sample. The light transmitted through the sample was imaged by an f=100 mm lens and the camera lens system (1.0 f/#) onto the focal pane array (FPA) in the IR camera. A computer provided synchronization of the ECQCL scan with the FPA acquisition and saved the image data. (b) Hypercubes consisting of 300 images acquired at different wavelengths were obtained by the system. (c) Measured output power of the ECQCL over its tuning range.

Fig. 2.
Fig. 2.

Hyperspectral imaging of methanol vapor. (a) Absorbance spectrum of methanol vapor from the quantitative NWIR spectral database for a concentration of 1 ppm and path length of 1 m. (b) Typical absorbance spectrum from a pixel of the hyperspectral system calculated using Eq. (1). (c) Image of methanol concentration in ppm·m for the entire scene, plotted according to the color bar shown. The concentration is highest just above the liquid methanol receptacle, seen at the bottom of the image.

Fig. 3.
Fig. 3.

(1.81 MB) Movie of methanol evaporation, playing in real time at a frame rate of 25 Hz, obtained by imaging the scene at the peak absorption wavelength of 1033.5 cm-1. The color bar shows the measured absorbance.[Media 1]

Fig. 4.
Fig. 4.

Chemical imaging of sample containing methanol and ethanol liquid. (a) Three absorbance spectra from different points in the hyperspectral image, showing mostly methanol (green), mostly ethanol (blue) and a mixture of both (red). (b) Absorbance spectra of pure liquid methanol (green) and pure liquid ethanol (blue) obtained using the ECQCL system and a point detector. (c) Methanol concentration (fit coefficient) obtained by a least-squares fit of the reference spectra. (d) Ethanol concentration obtained by the same method.

Fig. 5.
Fig. 5.

Chemical imaging of solid polymers. (a) Absorbance spectra of polypropylene (light blue), vinyl (green), polystyrene (orange), and LDPE (red) taken from pixels of the hyperspectral image. (b) Color-coding of image by PCA. The gray-scale image displays the average absorbance over the wavelength scan. The five data clusters obtained from the PCA were color coded to match the spectra shown in (a) and superimposed on the gray-scale image, efficiently identifying the different polymers and the background (dark blue).

Equations (1)

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A ( m , n , v ¯ ) = log 10 I sample ( m , n , v ¯ ) I background ( m , n ) I laser ( m , n , v ¯ ) I background ( m , n )

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