Abstract

Coherent anti-Stokes Raman scattering (CARS) associated with the second-order Raman process has been confirmed in diamond. Frequency dependence of CARS was analyzed using two-color synchronously-generated picosecond pulses. Resonance enhancement of χ (3) was observed at an energy shift corresponding to the overtone ∑ branch (K point) phonon, as well as the fundamental Raman-active Γ(25+) phonon. The excitation spectrum of CARS at the two-phonon resonance region showed dispersive dependence, reflecting the interference of resonant CARS and nonresonant four-wave mixing scattering.

© 2009 Optical Society of America

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  1. Y. R. Shen, The Principles of Nonlinear Optics (Wiley, New York 1984), pp. 266-285.
  2. H. Matsuki, K. Inoue, and E. Hanamura, "Multiple coherent anti-Stokes Raman scattering due to phonon grating in KNbO3 induced by crossed beams of two-color femtosecond pulses," Phys. Rev. B 75, 024102 (2007).
    [CrossRef]
  3. K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
    [CrossRef]
  4. M. Zhi and A. V. Sokolov, "Broadband coherent ligh generation in a Raman-active crystal driven by two-color femtosecond laser pulses," Opt. Lett. 32, 2251-2253 (2007).
    [CrossRef] [PubMed]
  5. M. D. Levenson, C. Flytzanis, and N. Bloembergen, "Interference of resonant and nonresonant three-wave mixing in diamond," Phys. Rev. B 6, 3962-3965 (1972).
    [CrossRef]
  6. G. L. Eesley and M. D. Levenson, "Coherent, nonlinear two-phonon Raman spectra of diamond," Opt. Lett. 3, 178-180 (1978).
    [CrossRef] [PubMed]
  7. A. A. Kaminskii, V. G. Ralchenko, V. I. Konov, and H. J. Eichler, "High-order Stokes and anti-Stokes Raman generation in CVD diamond," Phys. Status Solidi C 242, R4-R6 (2004).
  8. K. Ishioka, M. Hase, M. Kitajima, and H. Petek, "Coherent optical phonons in diamond," Appl. Phys. Lett. 89, 231916 (2006).
    [CrossRef]
  9. M. Zhi, X. Wang, and A. V. Sokolov, "Broadband coherent light generation in diamond driven by femtosecond pulses," Opt. Express 16, 12139-12147 (2008).
    [CrossRef] [PubMed]
  10. S. A. Solin and A. K. Ramdas, "Raman spectrum of diamond," Phys. Rev. B 1, 1687-1698 (1969).
    [CrossRef]
  11. E. Matsubara, T. Sekikawa, and M. Yamashita, "Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature," Appl. Phys. Lett. 92, 071104 (2008).
    [CrossRef]
  12. E. Hanamura, J. Kato, K. Inoue, and Y. Tanabe, "Multistep anti-Stokes Raman scattering by coherent gratings of Brillouin zone edge phonons," J. Phys. Soc. Jpn. 77, 034401 (2008).
    [CrossRef]
  13. R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
    [CrossRef]
  14. J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
    [CrossRef]
  15. M. D. Levenson and N. Bloembergen, "Dispersion of the nonlinear optical susceptibilities of organic liquids and solutions," J. Chem. Phys. 60, 1323-1327 (1974).
    [CrossRef]
  16. A. M. Zheltikov, "Theoretical introduction to nanoCARS: a local probing of nanocomposite materials with spectral profiles of coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 36, 176-182 (2005).
    [CrossRef]
  17. Y. R. Shen, "A note on two-phonon coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 10, 110-112 (1981).
    [CrossRef]

2008 (3)

E. Matsubara, T. Sekikawa, and M. Yamashita, "Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature," Appl. Phys. Lett. 92, 071104 (2008).
[CrossRef]

E. Hanamura, J. Kato, K. Inoue, and Y. Tanabe, "Multistep anti-Stokes Raman scattering by coherent gratings of Brillouin zone edge phonons," J. Phys. Soc. Jpn. 77, 034401 (2008).
[CrossRef]

M. Zhi, X. Wang, and A. V. Sokolov, "Broadband coherent light generation in diamond driven by femtosecond pulses," Opt. Express 16, 12139-12147 (2008).
[CrossRef] [PubMed]

2007 (3)

M. Zhi and A. V. Sokolov, "Broadband coherent ligh generation in a Raman-active crystal driven by two-color femtosecond laser pulses," Opt. Lett. 32, 2251-2253 (2007).
[CrossRef] [PubMed]

H. Matsuki, K. Inoue, and E. Hanamura, "Multiple coherent anti-Stokes Raman scattering due to phonon grating in KNbO3 induced by crossed beams of two-color femtosecond pulses," Phys. Rev. B 75, 024102 (2007).
[CrossRef]

K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
[CrossRef]

2006 (1)

K. Ishioka, M. Hase, M. Kitajima, and H. Petek, "Coherent optical phonons in diamond," Appl. Phys. Lett. 89, 231916 (2006).
[CrossRef]

2005 (1)

A. M. Zheltikov, "Theoretical introduction to nanoCARS: a local probing of nanocomposite materials with spectral profiles of coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 36, 176-182 (2005).
[CrossRef]

2004 (1)

A. A. Kaminskii, V. G. Ralchenko, V. I. Konov, and H. J. Eichler, "High-order Stokes and anti-Stokes Raman generation in CVD diamond," Phys. Status Solidi C 242, R4-R6 (2004).

2002 (1)

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

1998 (1)

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

1981 (1)

Y. R. Shen, "A note on two-phonon coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 10, 110-112 (1981).
[CrossRef]

1978 (1)

1974 (1)

M. D. Levenson and N. Bloembergen, "Dispersion of the nonlinear optical susceptibilities of organic liquids and solutions," J. Chem. Phys. 60, 1323-1327 (1974).
[CrossRef]

1972 (1)

M. D. Levenson, C. Flytzanis, and N. Bloembergen, "Interference of resonant and nonresonant three-wave mixing in diamond," Phys. Rev. B 6, 3962-3965 (1972).
[CrossRef]

1969 (1)

S. A. Solin and A. K. Ramdas, "Raman spectrum of diamond," Phys. Rev. B 1, 1687-1698 (1969).
[CrossRef]

Alvarenga, A. D.

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

Anthony, T. R.

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

Bloembergen, N.

M. D. Levenson and N. Bloembergen, "Dispersion of the nonlinear optical susceptibilities of organic liquids and solutions," J. Chem. Phys. 60, 1323-1327 (1974).
[CrossRef]

M. D. Levenson, C. Flytzanis, and N. Bloembergen, "Interference of resonant and nonresonant three-wave mixing in diamond," Phys. Rev. B 6, 3962-3965 (1972).
[CrossRef]

Dorner, B.

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

Eesley, G. L.

Eichler, H. J.

A. A. Kaminskii, V. G. Ralchenko, V. I. Konov, and H. J. Eichler, "High-order Stokes and anti-Stokes Raman generation in CVD diamond," Phys. Status Solidi C 242, R4-R6 (2004).

Flytzanis, C.

M. D. Levenson, C. Flytzanis, and N. Bloembergen, "Interference of resonant and nonresonant three-wave mixing in diamond," Phys. Rev. B 6, 3962-3965 (1972).
[CrossRef]

Grimsditch, M.

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

Hanamura, E.

E. Hanamura, J. Kato, K. Inoue, and Y. Tanabe, "Multistep anti-Stokes Raman scattering by coherent gratings of Brillouin zone edge phonons," J. Phys. Soc. Jpn. 77, 034401 (2008).
[CrossRef]

H. Matsuki, K. Inoue, and E. Hanamura, "Multiple coherent anti-Stokes Raman scattering due to phonon grating in KNbO3 induced by crossed beams of two-color femtosecond pulses," Phys. Rev. B 75, 024102 (2007).
[CrossRef]

Hanumura, E.

K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
[CrossRef]

Hase, M.

K. Ishioka, M. Hase, M. Kitajima, and H. Petek, "Coherent optical phonons in diamond," Appl. Phys. Lett. 89, 231916 (2006).
[CrossRef]

Inoue, K.

E. Hanamura, J. Kato, K. Inoue, and Y. Tanabe, "Multistep anti-Stokes Raman scattering by coherent gratings of Brillouin zone edge phonons," J. Phys. Soc. Jpn. 77, 034401 (2008).
[CrossRef]

K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
[CrossRef]

H. Matsuki, K. Inoue, and E. Hanamura, "Multiple coherent anti-Stokes Raman scattering due to phonon grating in KNbO3 induced by crossed beams of two-color femtosecond pulses," Phys. Rev. B 75, 024102 (2007).
[CrossRef]

Ishioka, K.

K. Ishioka, M. Hase, M. Kitajima, and H. Petek, "Coherent optical phonons in diamond," Appl. Phys. Lett. 89, 231916 (2006).
[CrossRef]

Kainzmaier, H.

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

Kaminskii, A. A.

A. A. Kaminskii, V. G. Ralchenko, V. I. Konov, and H. J. Eichler, "High-order Stokes and anti-Stokes Raman generation in CVD diamond," Phys. Status Solidi C 242, R4-R6 (2004).

Kato, J.

E. Hanamura, J. Kato, K. Inoue, and Y. Tanabe, "Multistep anti-Stokes Raman scattering by coherent gratings of Brillouin zone edge phonons," J. Phys. Soc. Jpn. 77, 034401 (2008).
[CrossRef]

K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
[CrossRef]

Kim, H.

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

Kitajima, M.

K. Ishioka, M. Hase, M. Kitajima, and H. Petek, "Coherent optical phonons in diamond," Appl. Phys. Lett. 89, 231916 (2006).
[CrossRef]

Konov, V. I.

A. A. Kaminskii, V. G. Ralchenko, V. I. Konov, and H. J. Eichler, "High-order Stokes and anti-Stokes Raman generation in CVD diamond," Phys. Status Solidi C 242, R4-R6 (2004).

Krisch, M.

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

Kulda, J.

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

Levenson, M. D.

G. L. Eesley and M. D. Levenson, "Coherent, nonlinear two-phonon Raman spectra of diamond," Opt. Lett. 3, 178-180 (1978).
[CrossRef] [PubMed]

M. D. Levenson and N. Bloembergen, "Dispersion of the nonlinear optical susceptibilities of organic liquids and solutions," J. Chem. Phys. 60, 1323-1327 (1974).
[CrossRef]

M. D. Levenson, C. Flytzanis, and N. Bloembergen, "Interference of resonant and nonresonant three-wave mixing in diamond," Phys. Rev. B 6, 3962-3965 (1972).
[CrossRef]

Lorenzen, M.

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

Matsubara, E.

E. Matsubara, T. Sekikawa, and M. Yamashita, "Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature," Appl. Phys. Lett. 92, 071104 (2008).
[CrossRef]

K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
[CrossRef]

Matsuki, H.

H. Matsuki, K. Inoue, and E. Hanamura, "Multiple coherent anti-Stokes Raman scattering due to phonon grating in KNbO3 induced by crossed beams of two-color femtosecond pulses," Phys. Rev. B 75, 024102 (2007).
[CrossRef]

K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
[CrossRef]

Petek, H.

K. Ishioka, M. Hase, M. Kitajima, and H. Petek, "Coherent optical phonons in diamond," Appl. Phys. Lett. 89, 231916 (2006).
[CrossRef]

Ralchenko, V. G.

A. A. Kaminskii, V. G. Ralchenko, V. I. Konov, and H. J. Eichler, "High-order Stokes and anti-Stokes Raman generation in CVD diamond," Phys. Status Solidi C 242, R4-R6 (2004).

Ramdas, A. K.

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

S. A. Solin and A. K. Ramdas, "Raman spectrum of diamond," Phys. Rev. B 1, 1687-1698 (1969).
[CrossRef]

Rodriguez, S.

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

Sekikawa, T.

E. Matsubara, T. Sekikawa, and M. Yamashita, "Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature," Appl. Phys. Lett. 92, 071104 (2008).
[CrossRef]

Shen, Y. R.

Y. R. Shen, "A note on two-phonon coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 10, 110-112 (1981).
[CrossRef]

Sokolov, A. V.

Solin, S. A.

S. A. Solin and A. K. Ramdas, "Raman spectrum of diamond," Phys. Rev. B 1, 1687-1698 (1969).
[CrossRef]

Strauch, D.

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

Tanabe, Y.

E. Hanamura, J. Kato, K. Inoue, and Y. Tanabe, "Multistep anti-Stokes Raman scattering by coherent gratings of Brillouin zone edge phonons," J. Phys. Soc. Jpn. 77, 034401 (2008).
[CrossRef]

Vogelgesang, R.

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

Wang, X.

Yamashita, M.

E. Matsubara, T. Sekikawa, and M. Yamashita, "Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature," Appl. Phys. Lett. 92, 071104 (2008).
[CrossRef]

Zheltikov, A. M.

A. M. Zheltikov, "Theoretical introduction to nanoCARS: a local probing of nanocomposite materials with spectral profiles of coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 36, 176-182 (2005).
[CrossRef]

Zhi, M.

Appl. Phys. Lett. (2)

E. Matsubara, T. Sekikawa, and M. Yamashita, "Generation of ultrashort optical pulses using multiple coherent anti-Stokes Raman scattering in a crystal at room temperature," Appl. Phys. Lett. 92, 071104 (2008).
[CrossRef]

K. Ishioka, M. Hase, M. Kitajima, and H. Petek, "Coherent optical phonons in diamond," Appl. Phys. Lett. 89, 231916 (2006).
[CrossRef]

J. Chem. Phys. (1)

M. D. Levenson and N. Bloembergen, "Dispersion of the nonlinear optical susceptibilities of organic liquids and solutions," J. Chem. Phys. 60, 1323-1327 (1974).
[CrossRef]

J. Phys. Soc. Jpn. (1)

E. Hanamura, J. Kato, K. Inoue, and Y. Tanabe, "Multistep anti-Stokes Raman scattering by coherent gratings of Brillouin zone edge phonons," J. Phys. Soc. Jpn. 77, 034401 (2008).
[CrossRef]

J. Raman Spectroscopy (2)

A. M. Zheltikov, "Theoretical introduction to nanoCARS: a local probing of nanocomposite materials with spectral profiles of coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 36, 176-182 (2005).
[CrossRef]

Y. R. Shen, "A note on two-phonon coherent anti-Stokes Raman scattering," J. Raman Spectroscopy 10, 110-112 (1981).
[CrossRef]

Opt. Express (1)

Opt. Lett. (2)

Phys. Rev. B (6)

S. A. Solin and A. K. Ramdas, "Raman spectrum of diamond," Phys. Rev. B 1, 1687-1698 (1969).
[CrossRef]

R. Vogelgesang, A. D. Alvarenga, H. Kim, A. K. Ramdas, and S. Rodriguez, M. Grimsditch, and T. R. Anthony, "Multiphonon Raman and infrared spectra of isotopically controlled diamond," Phys. Rev. B 58, 5408-5416 (1998).
[CrossRef]

J. Kulda, H. Kainzmaier, D. Strauch, B. Dorner, M. Lorenzen, and M. Krisch, "Overbending of the longitudinal optical phonon branch in diamond as evidenced by inelastic neutron and x-ray scattering," Phys. Rev. B 66, 241202 (2002).
[CrossRef]

H. Matsuki, K. Inoue, and E. Hanamura, "Multiple coherent anti-Stokes Raman scattering due to phonon grating in KNbO3 induced by crossed beams of two-color femtosecond pulses," Phys. Rev. B 75, 024102 (2007).
[CrossRef]

K. Inoue, J. Kato, E. Hanumura, H. Matsuki, and E. Matsubara, "Broadband coherent radiation based on peculiar multiple Raman scattering by laser-induced phonon gratings in TiO2," Phys. Rev. B 76, 041101 (2007).
[CrossRef]

M. D. Levenson, C. Flytzanis, and N. Bloembergen, "Interference of resonant and nonresonant three-wave mixing in diamond," Phys. Rev. B 6, 3962-3965 (1972).
[CrossRef]

Phys. Status Solidi C (1)

A. A. Kaminskii, V. G. Ralchenko, V. I. Konov, and H. J. Eichler, "High-order Stokes and anti-Stokes Raman generation in CVD diamond," Phys. Status Solidi C 242, R4-R6 (2004).

Other (1)

Y. R. Shen, The Principles of Nonlinear Optics (Wiley, New York 1984), pp. 266-285.

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Figures (5)

Fig. 1.
Fig. 1.

(a) Transition scheme and (b) spatial arrangement for the CARS generation.

Fig. 2.
Fig. 2.

Spontaneous Raman spectrum in the present sample of diamond. It was excited by the 512.45 nm line of an Ar+ laser. The blue line is a ×200 magnified view of the red line. The dotted line shows background noise levels.

Fig. 3.
Fig. 3.

Comparison between the spectra of the excitation pulses and those of the CARS signals which were resonant with the Raman-active Γ(25+) phonon. (a) ω 2 pulse, (b) ω 1 pulse, (c) first-order CARS, and (d) second-order CARS. A spontaneous Raman spectrum pumped by ω 1 pulse is also shown by the dotted line in (a).

Fig. 4.
Fig. 4.

CARS intensity as a function of energy shift between the two excitation pulses, ω 1-ω 2 (blue dots). Spontaneous Raman spectrum excited by the ω1 pulse is also plotted (red line).

Fig. 5.
Fig. 5.

CARS intensity as a function of excitation energy shift ω 1-ω 2, close to the resonance of 2Ω. Model function is also plotted by the red line, where χ (3) R/χ (3) NR=0.25, Γ= 3.5 cm-1, and Ω=2460 cm-1 in Eq. (1).

Equations (1)

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χ CARS ( 3 ) = χ NR ( 3 ) χ R ( 3 ) Γ Δ + i Γ ,

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