Abstract

We measured the third-harmonic spectrum for each of four squaraine dyes in chloroform. By fitting the experimental dispersion of the third-order susceptibility, γ, to a four-level sum-over-states model, we determine the strength and the location of the lowest-lying two-photon-like transition. In each case, we find that the lowest two-photon-like state appears just above the dominant linear absorption peak in energy and that the transition moment to that state makes a significant contribution to the nonlinearity, as do transition moments to one or more higher-lying two-photon-like states in the ultraviolet. The spectra of two of these dyes contain additional features, evidencing a nonzero dipole moment difference between the ground and the first excited-state dipole moments that we attribute to asymmetry in their structures. From our measurements, we also predict the dispersion of the real and the imaginary optical Kerr susceptibilities in the near infrared for two of these dyes.

© 1995 Optical Society of America

Full Article  |  PDF Article

References

  • View by:
  • |
  • |
  • |

  1. K. D. Singer and J. H. Andrews, "Quadratic nonlinear optics in poled polymer films: From physics to devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices, J. Zyss, ed. (Academic, New York, 1994), pp. 245–298.
  2. K. D. Singer, J. E. Sohn, L. A. King, H. M. Gordon, H. E. Katz, and C. W. Dirk, "Second-order nonlinear-optical properties of donor- and acceptor-substituted aromatic compounds," J. Opt. Soc. Am. B 6, 1339–1350 (1989).
    [CrossRef]
  3. J. W. Wu, J. R. Heflin, R. A. Norwood, K. Y. Wong, O. Zamani-Khamiri, A. F. Garito, P. Kalyanaraman, and J. Sounik, "Nonlinear-optical processes in lower-dimensional conjugated structures," J. Opt. Soc. Am. B 6, 707–720 (1989).
    [CrossRef]
  4. B. M. Pierce, "A theoretical analysis of the third-order nonlinear optical properties of linear cyanines and polyenes," in Nonlinear Optical Properties of Organic Materials IV, K. D. Singer, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1560, 148–161 (1991).
    [CrossRef]
  5. M. G. Kuzyk and C. W. Dirk, "Effects of centrosymmetry on the nonresonant electronic third-order nonlinear optical susceptibility," Phys. Rev. A 41, 5098–5109 (1990).
    [CrossRef] [PubMed]
  6. C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
    [CrossRef]
  7. J. R. Heflin, Y. M. Cai, and A. F. Garito, "Dispersion measurements of electric-field-induced second-harmonic generation and third-harmonic generation in conjugated linear chains," J. Opt. Soc. Am. B 8, 2132–2147 (1991).
    [CrossRef]
  8. J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
    [CrossRef]
  9. Y. Z. Yu, R. F. Shi, A. F. Garito, and C. H. Grossman, "Origin of negative x(3) in squaraines: experimental observation of two-photon state," Opt. Lett. 19, 786–788 (1994).
    [CrossRef] [PubMed]
  10. S. Aramaki, W. Torruellas, R. Zanoni, and G. I. Stegeman, "Tunable third harmonic generation of trans-β–carotene," Opt. Commun. 85, 527–535 (1991).
    [CrossRef]
  11. M. G. Kuzyk, J. E. Sohn, and C. W. Dirk, "Mechanisms of quadratic electro-optic modulation of dye doped polymer systems," J. Opt. Soc. Am. B 7, 842–858 (1990).
    [CrossRef]
  12. C. W. Dirk and M. G. Kuzyk, "Squarilium dye-doped polymer systems as quadratic electrooptic materials," Chem. Mater. 2, 4–6 (1990).
    [CrossRef]
  13. J. H. Andrews, J. D. V. Khaydarov, and K. D. Singer, "Contribution of the 2Ag state to the third-order optical nonlinearity in a squaraine dye," Opt. Lett. 19, 984–986, "Errata," 19, 1909 (1994).
  14. J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).
  15. Q. L. Zhou, R. F. Shi, O. Zamani-Khamari, and A. F. Garito, "Negative third-order optical responses in squaraines," Nonlinear Opt. 6, 145–154 (1993).
  16. D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
    [CrossRef]
  17. F. Meyers, S. R. Marder, B. M. Pierce, and J. L. Bredas, "Electric field modulated nonlinear optical properties of donor-acceptor polyenes: sum-over-states investigation of the relationship between molecular polarizabilities (α, β, and ϒ) and bond length alternation," J. Am. Chem. Soc. 116, 10703–10714 (1994).
    [CrossRef]
  18. S. Etemad, G. L. Baker, and Z. G. Soos, "Third-order NLO processes in polydiacetylenes: physics, materials, and devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices (Academic, New York, 1994), 433–465.
  19. S. R. Marder, C. B. Gorman, L.-T. Cheng, and B. G. Tiemann, "Optimizing the second-order optical nonlinearities of organic molecules: asymmetric cyanines and highly polarized polyenes," in Nonlinear Optical Properties of Organic Materials V, D. J. Williams, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1775, 19–31 (1992).
    [CrossRef]
  20. R. W. Bigelow and H.-J. Freund, "An MNDO and CNDO/S(S+ DES CI) study of the structural and electronic properties of a model squaraine dye and related cyanine," Chem. Phys. 107, 159–174 (1986).
    [CrossRef]
  21. C. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. King, "Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities," Chem. Mater. 2, 700–705 (1990); "Errata," 3, 207 (1991).
    [CrossRef]
  22. C. Poga, M. G. Kuzyk, S. Martinez, and C. W. Dirk, "Quadratic electroabsorption spectroscopy as a probe of x(3) mechanisms in dye-doped polymers," in Nonlinear Optical Properties of Organic Materials VI, G. R. Moehlmann, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 2025, 363–372 (1993).
    [CrossRef]
  23. C. Poga, T. M. Brown, M. G. Kuzyk, and C. W. Dirk, "Characterization of the excited states of a squaraine molecule with quadratic electroabsorption spectroscopy," J. Opt. Soc. Am. B 12, 531–543 (1995).
    [CrossRef]
  24. A. Agnesi, G. C. Reali, V. Kubecek, S. Kumazaki, Y. Takagi, and K. Yoshihara, "β-barium borate and lithium triborate picosecond parametric oscillators pumped by a frequencytripled passive negative-feedback mode-locked Nd:YAG laser," J. Opt. Soc. Am. B 10, 2211–2217 (1993).
    [CrossRef]
  25. J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse compression in a synchronously pumped optical parametric oscillator due to group velocity mismatch," Opt. Lett. 19, 831–833 (1994).
    [CrossRef] [PubMed]
  26. J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "20-fold pulse compression in a synchronously pumped optical parametric oscillator," Appl. Phys. Lett. 65, 1614–1616 (1994).
    [CrossRef]
  27. J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse-compression mechanism in a synchronously pumped optical parametric oscillator," J. Opt. Soc. Am. B 2199–2208 (1995).
    [CrossRef]
  28. F. Kajzar and J. Messier, "Original technique for third-harmonic-generation measurements in liquids," Rev. Sci. Instrum. 58, 2081–2085 (1987).
    [CrossRef]
  29. Optical Glass, Schott Glass Technologies Inc. catalog (Schott Glass, Duryea, Pa., 1990).
  30. V. Mizrahi, K. W. DeLong, G. I. Stegeman, M. A. Saifi, and M. J. Andrejco, "Two-photon absorption as a limitation to all-optical switching," Opt. Lett. 14, 1140–1142 (1989).
    [CrossRef] [PubMed]
  31. F. Kajzar, S. Etemad, G. L. Baker, and J. Messier, "Frequency dependence of the large, electronic x(3) in polyacetylene," Solid State Commun. 63, 1113–1117 (1987).
    [CrossRef]
  32. S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
    [CrossRef] [PubMed]
  33. S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
    [CrossRef]
  34. S. R. Marder, C. B. Gorman, B. G. Tiemann, and L.-T. Cheng, "Stronger acceptors can diminish nonlinear optical response in simple donor-acceptor polyenes," J. Am. Chem. Soc. 115, 3006–3007 (1993).
    [CrossRef]
  35. C. C. Teng and A. F. Garito, "Dispersion of the second-order optical susceptibility of organic systems," Phys. Rev. B 28, 6766–6773 (1983).
    [CrossRef]

1995 (4)

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse-compression mechanism in a synchronously pumped optical parametric oscillator," J. Opt. Soc. Am. B 2199–2208 (1995).
[CrossRef]

C. Poga, T. M. Brown, M. G. Kuzyk, and C. W. Dirk, "Characterization of the excited states of a squaraine molecule with quadratic electroabsorption spectroscopy," J. Opt. Soc. Am. B 12, 531–543 (1995).
[CrossRef]

1994 (5)

Y. Z. Yu, R. F. Shi, A. F. Garito, and C. H. Grossman, "Origin of negative x(3) in squaraines: experimental observation of two-photon state," Opt. Lett. 19, 786–788 (1994).
[CrossRef] [PubMed]

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse compression in a synchronously pumped optical parametric oscillator due to group velocity mismatch," Opt. Lett. 19, 831–833 (1994).
[CrossRef] [PubMed]

J. H. Andrews, J. D. V. Khaydarov, and K. D. Singer, "Contribution of the 2Ag state to the third-order optical nonlinearity in a squaraine dye," Opt. Lett. 19, 984–986, "Errata," 19, 1909 (1994).

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "20-fold pulse compression in a synchronously pumped optical parametric oscillator," Appl. Phys. Lett. 65, 1614–1616 (1994).
[CrossRef]

F. Meyers, S. R. Marder, B. M. Pierce, and J. L. Bredas, "Electric field modulated nonlinear optical properties of donor-acceptor polyenes: sum-over-states investigation of the relationship between molecular polarizabilities (α, β, and ϒ) and bond length alternation," J. Am. Chem. Soc. 116, 10703–10714 (1994).
[CrossRef]

1993 (5)

Q. L. Zhou, R. F. Shi, O. Zamani-Khamari, and A. F. Garito, "Negative third-order optical responses in squaraines," Nonlinear Opt. 6, 145–154 (1993).

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

S. R. Marder, C. B. Gorman, B. G. Tiemann, and L.-T. Cheng, "Stronger acceptors can diminish nonlinear optical response in simple donor-acceptor polyenes," J. Am. Chem. Soc. 115, 3006–3007 (1993).
[CrossRef]

A. Agnesi, G. C. Reali, V. Kubecek, S. Kumazaki, Y. Takagi, and K. Yoshihara, "β-barium borate and lithium triborate picosecond parametric oscillators pumped by a frequencytripled passive negative-feedback mode-locked Nd:YAG laser," J. Opt. Soc. Am. B 10, 2211–2217 (1993).
[CrossRef]

1992 (1)

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

1991 (2)

1990 (4)

M. G. Kuzyk, J. E. Sohn, and C. W. Dirk, "Mechanisms of quadratic electro-optic modulation of dye doped polymer systems," J. Opt. Soc. Am. B 7, 842–858 (1990).
[CrossRef]

C. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. King, "Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities," Chem. Mater. 2, 700–705 (1990); "Errata," 3, 207 (1991).
[CrossRef]

C. W. Dirk and M. G. Kuzyk, "Squarilium dye-doped polymer systems as quadratic electrooptic materials," Chem. Mater. 2, 4–6 (1990).
[CrossRef]

M. G. Kuzyk and C. W. Dirk, "Effects of centrosymmetry on the nonresonant electronic third-order nonlinear optical susceptibility," Phys. Rev. A 41, 5098–5109 (1990).
[CrossRef] [PubMed]

1989 (3)

1987 (2)

F. Kajzar and J. Messier, "Original technique for third-harmonic-generation measurements in liquids," Rev. Sci. Instrum. 58, 2081–2085 (1987).
[CrossRef]

F. Kajzar, S. Etemad, G. L. Baker, and J. Messier, "Frequency dependence of the large, electronic x(3) in polyacetylene," Solid State Commun. 63, 1113–1117 (1987).
[CrossRef]

1986 (1)

R. W. Bigelow and H.-J. Freund, "An MNDO and CNDO/S(S+ DES CI) study of the structural and electronic properties of a model squaraine dye and related cyanine," Chem. Phys. 107, 159–174 (1986).
[CrossRef]

1983 (1)

C. C. Teng and A. F. Garito, "Dispersion of the second-order optical susceptibility of organic systems," Phys. Rev. B 28, 6766–6773 (1983).
[CrossRef]

Agnesi, A.

Andrejco, M. J.

Andrews, J. H.

J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse-compression mechanism in a synchronously pumped optical parametric oscillator," J. Opt. Soc. Am. B 2199–2208 (1995).
[CrossRef]

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse compression in a synchronously pumped optical parametric oscillator due to group velocity mismatch," Opt. Lett. 19, 831–833 (1994).
[CrossRef] [PubMed]

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "20-fold pulse compression in a synchronously pumped optical parametric oscillator," Appl. Phys. Lett. 65, 1614–1616 (1994).
[CrossRef]

J. H. Andrews, J. D. V. Khaydarov, and K. D. Singer, "Contribution of the 2Ag state to the third-order optical nonlinearity in a squaraine dye," Opt. Lett. 19, 984–986, "Errata," 19, 1909 (1994).

K. D. Singer and J. H. Andrews, "Quadratic nonlinear optics in poled polymer films: From physics to devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices, J. Zyss, ed. (Academic, New York, 1994), pp. 245–298.

Aramaki, S.

S. Aramaki, W. Torruellas, R. Zanoni, and G. I. Stegeman, "Tunable third harmonic generation of trans-β–carotene," Opt. Commun. 85, 527–535 (1991).
[CrossRef]

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Baker, G. L.

F. Kajzar, S. Etemad, G. L. Baker, and J. Messier, "Frequency dependence of the large, electronic x(3) in polyacetylene," Solid State Commun. 63, 1113–1117 (1987).
[CrossRef]

S. Etemad, G. L. Baker, and Z. G. Soos, "Third-order NLO processes in polydiacetylenes: physics, materials, and devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices (Academic, New York, 1994), 433–465.

Biddle, S. L.

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

Bigelow, R. W.

R. W. Bigelow and H.-J. Freund, "An MNDO and CNDO/S(S+ DES CI) study of the structural and electronic properties of a model squaraine dye and related cyanine," Chem. Phys. 107, 159–174 (1986).
[CrossRef]

Bourhill, G.

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

Bredas, J. L.

F. Meyers, S. R. Marder, B. M. Pierce, and J. L. Bredas, "Electric field modulated nonlinear optical properties of donor-acceptor polyenes: sum-over-states investigation of the relationship between molecular polarizabilities (α, β, and ϒ) and bond length alternation," J. Am. Chem. Soc. 116, 10703–10714 (1994).
[CrossRef]

Brown, T. M.

Cai, Y. M.

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

J. R. Heflin, Y. M. Cai, and A. F. Garito, "Dispersion measurements of electric-field-induced second-harmonic generation and third-harmonic generation in conjugated linear chains," J. Opt. Soc. Am. B 8, 2132–2147 (1991).
[CrossRef]

Campos, G.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Cervantes-Lee, F.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Cha, M.

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Cheng, L.-T.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

S. R. Marder, C. B. Gorman, B. G. Tiemann, and L.-T. Cheng, "Stronger acceptors can diminish nonlinear optical response in simple donor-acceptor polyenes," J. Am. Chem. Soc. 115, 3006–3007 (1993).
[CrossRef]

S. R. Marder, C. B. Gorman, L.-T. Cheng, and B. G. Tiemann, "Optimizing the second-order optical nonlinearities of organic molecules: asymmetric cyanines and highly polarized polyenes," in Nonlinear Optical Properties of Organic Materials V, D. J. Williams, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1775, 19–31 (1992).
[CrossRef]

Chuang, K. C.

J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).

DeLong, K. W.

Dirk, C. W.

C. Poga, T. M. Brown, M. G. Kuzyk, and C. W. Dirk, "Characterization of the excited states of a squaraine molecule with quadratic electroabsorption spectroscopy," J. Opt. Soc. Am. B 12, 531–543 (1995).
[CrossRef]

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

C. W. Dirk and M. G. Kuzyk, "Squarilium dye-doped polymer systems as quadratic electrooptic materials," Chem. Mater. 2, 4–6 (1990).
[CrossRef]

C. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. King, "Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities," Chem. Mater. 2, 700–705 (1990); "Errata," 3, 207 (1991).
[CrossRef]

M. G. Kuzyk and C. W. Dirk, "Effects of centrosymmetry on the nonresonant electronic third-order nonlinear optical susceptibility," Phys. Rev. A 41, 5098–5109 (1990).
[CrossRef] [PubMed]

M. G. Kuzyk, J. E. Sohn, and C. W. Dirk, "Mechanisms of quadratic electro-optic modulation of dye doped polymer systems," J. Opt. Soc. Am. B 7, 842–858 (1990).
[CrossRef]

K. D. Singer, J. E. Sohn, L. A. King, H. M. Gordon, H. E. Katz, and C. W. Dirk, "Second-order nonlinear-optical properties of donor- and acceptor-substituted aromatic compounds," J. Opt. Soc. Am. B 6, 1339–1350 (1989).
[CrossRef]

C. Poga, M. G. Kuzyk, S. Martinez, and C. W. Dirk, "Quadratic electroabsorption spectroscopy as a probe of x(3) mechanisms in dye-doped polymers," in Nonlinear Optical Properties of Organic Materials VI, G. R. Moehlmann, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 2025, 363–372 (1993).
[CrossRef]

Etemad, S.

F. Kajzar, S. Etemad, G. L. Baker, and J. Messier, "Frequency dependence of the large, electronic x(3) in polyacetylene," Solid State Commun. 63, 1113–1117 (1987).
[CrossRef]

S. Etemad, G. L. Baker, and Z. G. Soos, "Third-order NLO processes in polydiacetylenes: physics, materials, and devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices (Academic, New York, 1994), 433–465.

Freund, H.-J.

R. W. Bigelow and H.-J. Freund, "An MNDO and CNDO/S(S+ DES CI) study of the structural and electronic properties of a model squaraine dye and related cyanine," Chem. Phys. 107, 159–174 (1986).
[CrossRef]

Garito, A. F.

Y. Z. Yu, R. F. Shi, A. F. Garito, and C. H. Grossman, "Origin of negative x(3) in squaraines: experimental observation of two-photon state," Opt. Lett. 19, 786–788 (1994).
[CrossRef] [PubMed]

Q. L. Zhou, R. F. Shi, O. Zamani-Khamari, and A. F. Garito, "Negative third-order optical responses in squaraines," Nonlinear Opt. 6, 145–154 (1993).

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

J. R. Heflin, Y. M. Cai, and A. F. Garito, "Dispersion measurements of electric-field-induced second-harmonic generation and third-harmonic generation in conjugated linear chains," J. Opt. Soc. Am. B 8, 2132–2147 (1991).
[CrossRef]

J. W. Wu, J. R. Heflin, R. A. Norwood, K. Y. Wong, O. Zamani-Khamiri, A. F. Garito, P. Kalyanaraman, and J. Sounik, "Nonlinear-optical processes in lower-dimensional conjugated structures," J. Opt. Soc. Am. B 6, 707–720 (1989).
[CrossRef]

C. C. Teng and A. F. Garito, "Dispersion of the second-order optical susceptibility of organic systems," Phys. Rev. B 28, 6766–6773 (1983).
[CrossRef]

Gilmour, S.

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

Gordon, H. M.

Gorman, C. B.

S. R. Marder, C. B. Gorman, B. G. Tiemann, and L.-T. Cheng, "Stronger acceptors can diminish nonlinear optical response in simple donor-acceptor polyenes," J. Am. Chem. Soc. 115, 3006–3007 (1993).
[CrossRef]

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

S. R. Marder, C. B. Gorman, L.-T. Cheng, and B. G. Tiemann, "Optimizing the second-order optical nonlinearities of organic molecules: asymmetric cyanines and highly polarized polyenes," in Nonlinear Optical Properties of Organic Materials V, D. J. Williams, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1775, 19–31 (1992).
[CrossRef]

Grossman, C. H.

Guo, D.

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Heflin, J. R.

Herndon, W. C.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Hull, D. L.

J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).

Kajzar, F.

F. Kajzar, S. Etemad, G. L. Baker, and J. Messier, "Frequency dependence of the large, electronic x(3) in polyacetylene," Solid State Commun. 63, 1113–1117 (1987).
[CrossRef]

F. Kajzar and J. Messier, "Original technique for third-harmonic-generation measurements in liquids," Rev. Sci. Instrum. 58, 2081–2085 (1987).
[CrossRef]

Kalamegham, P.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Kalyanaraman, P.

Katz, H. E.

C. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. King, "Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities," Chem. Mater. 2, 700–705 (1990); "Errata," 3, 207 (1991).
[CrossRef]

K. D. Singer, J. E. Sohn, L. A. King, H. M. Gordon, H. E. Katz, and C. W. Dirk, "Second-order nonlinear-optical properties of donor- and acceptor-substituted aromatic compounds," J. Opt. Soc. Am. B 6, 1339–1350 (1989).
[CrossRef]

Khaydarov, J. D. V.

J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse-compression mechanism in a synchronously pumped optical parametric oscillator," J. Opt. Soc. Am. B 2199–2208 (1995).
[CrossRef]

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse compression in a synchronously pumped optical parametric oscillator due to group velocity mismatch," Opt. Lett. 19, 831–833 (1994).
[CrossRef] [PubMed]

J. H. Andrews, J. D. V. Khaydarov, and K. D. Singer, "Contribution of the 2Ag state to the third-order optical nonlinearity in a squaraine dye," Opt. Lett. 19, 984–986, "Errata," 19, 1909 (1994).

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "20-fold pulse compression in a synchronously pumped optical parametric oscillator," Appl. Phys. Lett. 65, 1614–1616 (1994).
[CrossRef]

King, L. A.

C. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. King, "Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities," Chem. Mater. 2, 700–705 (1990); "Errata," 3, 207 (1991).
[CrossRef]

K. D. Singer, J. E. Sohn, L. A. King, H. M. Gordon, H. E. Katz, and C. W. Dirk, "Second-order nonlinear-optical properties of donor- and acceptor-substituted aromatic compounds," J. Opt. Soc. Am. B 6, 1339–1350 (1989).
[CrossRef]

Kubecek, V.

Kumazaki, S.

Kuzyk, M. G.

C. Poga, T. M. Brown, M. G. Kuzyk, and C. W. Dirk, "Characterization of the excited states of a squaraine molecule with quadratic electroabsorption spectroscopy," J. Opt. Soc. Am. B 12, 531–543 (1995).
[CrossRef]

M. G. Kuzyk and C. W. Dirk, "Effects of centrosymmetry on the nonresonant electronic third-order nonlinear optical susceptibility," Phys. Rev. A 41, 5098–5109 (1990).
[CrossRef] [PubMed]

M. G. Kuzyk, J. E. Sohn, and C. W. Dirk, "Mechanisms of quadratic electro-optic modulation of dye doped polymer systems," J. Opt. Soc. Am. B 7, 842–858 (1990).
[CrossRef]

C. W. Dirk and M. G. Kuzyk, "Squarilium dye-doped polymer systems as quadratic electrooptic materials," Chem. Mater. 2, 4–6 (1990).
[CrossRef]

C. Poga, M. G. Kuzyk, S. Martinez, and C. W. Dirk, "Quadratic electroabsorption spectroscopy as a probe of x(3) mechanisms in dye-doped polymers," in Nonlinear Optical Properties of Organic Materials VI, G. R. Moehlmann, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 2025, 363–372 (1993).
[CrossRef]

Ledoux, I.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Mansour, K.

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

Marder, S. R.

F. Meyers, S. R. Marder, B. M. Pierce, and J. L. Bredas, "Electric field modulated nonlinear optical properties of donor-acceptor polyenes: sum-over-states investigation of the relationship between molecular polarizabilities (α, β, and ϒ) and bond length alternation," J. Am. Chem. Soc. 116, 10703–10714 (1994).
[CrossRef]

S. R. Marder, C. B. Gorman, B. G. Tiemann, and L.-T. Cheng, "Stronger acceptors can diminish nonlinear optical response in simple donor-acceptor polyenes," J. Am. Chem. Soc. 115, 3006–3007 (1993).
[CrossRef]

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

S. R. Marder, C. B. Gorman, L.-T. Cheng, and B. G. Tiemann, "Optimizing the second-order optical nonlinearities of organic molecules: asymmetric cyanines and highly polarized polyenes," in Nonlinear Optical Properties of Organic Materials V, D. J. Williams, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1775, 19–31 (1992).
[CrossRef]

Martinez, S.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

C. Poga, M. G. Kuzyk, S. Martinez, and C. W. Dirk, "Quadratic electroabsorption spectroscopy as a probe of x(3) mechanisms in dye-doped polymers," in Nonlinear Optical Properties of Organic Materials VI, G. R. Moehlmann, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 2025, 363–372 (1993).
[CrossRef]

Mazumdar, S.

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Messier, J.

F. Kajzar and J. Messier, "Original technique for third-harmonic-generation measurements in liquids," Rev. Sci. Instrum. 58, 2081–2085 (1987).
[CrossRef]

F. Kajzar, S. Etemad, G. L. Baker, and J. Messier, "Frequency dependence of the large, electronic x(3) in polyacetylene," Solid State Commun. 63, 1113–1117 (1987).
[CrossRef]

Meyers, F.

F. Meyers, S. R. Marder, B. M. Pierce, and J. L. Bredas, "Electric field modulated nonlinear optical properties of donor-acceptor polyenes: sum-over-states investigation of the relationship between molecular polarizabilities (α, β, and ϒ) and bond length alternation," J. Am. Chem. Soc. 116, 10703–10714 (1994).
[CrossRef]

Mizrahi, V.

Neher, D.

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Norwood, R. A.

Perry, J. W.

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

Pierce, B. M.

F. Meyers, S. R. Marder, B. M. Pierce, and J. L. Bredas, "Electric field modulated nonlinear optical properties of donor-acceptor polyenes: sum-over-states investigation of the relationship between molecular polarizabilities (α, β, and ϒ) and bond length alternation," J. Am. Chem. Soc. 116, 10703–10714 (1994).
[CrossRef]

B. M. Pierce, "A theoretical analysis of the third-order nonlinear optical properties of linear cyanines and polyenes," in Nonlinear Optical Properties of Organic Materials IV, K. D. Singer, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1560, 148–161 (1991).
[CrossRef]

Poga, C.

C. Poga, T. M. Brown, M. G. Kuzyk, and C. W. Dirk, "Characterization of the excited states of a squaraine molecule with quadratic electroabsorption spectroscopy," J. Opt. Soc. Am. B 12, 531–543 (1995).
[CrossRef]

C. Poga, M. G. Kuzyk, S. Martinez, and C. W. Dirk, "Quadratic electroabsorption spectroscopy as a probe of x(3) mechanisms in dye-doped polymers," in Nonlinear Optical Properties of Organic Materials VI, G. R. Moehlmann, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 2025, 363–372 (1993).
[CrossRef]

Reali, G. C.

Rodenberger, D. C.

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

Saifi, M. A.

Schilling, M. L.

C. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. King, "Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities," Chem. Mater. 2, 700–705 (1990); "Errata," 3, 207 (1991).
[CrossRef]

Selnau, H.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Shi, R. F.

Y. Z. Yu, R. F. Shi, A. F. Garito, and C. H. Grossman, "Origin of negative x(3) in squaraines: experimental observation of two-photon state," Opt. Lett. 19, 786–788 (1994).
[CrossRef] [PubMed]

Q. L. Zhou, R. F. Shi, O. Zamani-Khamari, and A. F. Garito, "Negative third-order optical responses in squaraines," Nonlinear Opt. 6, 145–154 (1993).

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

Singer, K. D.

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse-compression mechanism in a synchronously pumped optical parametric oscillator," J. Opt. Soc. Am. B 2199–2208 (1995).
[CrossRef]

J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse compression in a synchronously pumped optical parametric oscillator due to group velocity mismatch," Opt. Lett. 19, 831–833 (1994).
[CrossRef] [PubMed]

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "20-fold pulse compression in a synchronously pumped optical parametric oscillator," Appl. Phys. Lett. 65, 1614–1616 (1994).
[CrossRef]

J. H. Andrews, J. D. V. Khaydarov, and K. D. Singer, "Contribution of the 2Ag state to the third-order optical nonlinearity in a squaraine dye," Opt. Lett. 19, 984–986, "Errata," 19, 1909 (1994).

K. D. Singer, J. E. Sohn, L. A. King, H. M. Gordon, H. E. Katz, and C. W. Dirk, "Second-order nonlinear-optical properties of donor- and acceptor-substituted aromatic compounds," J. Opt. Soc. Am. B 6, 1339–1350 (1989).
[CrossRef]

K. D. Singer and J. H. Andrews, "Quadratic nonlinear optics in poled polymer films: From physics to devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices, J. Zyss, ed. (Academic, New York, 1994), pp. 245–298.

Sohn, J. E.

Soos, Z. G.

S. Etemad, G. L. Baker, and Z. G. Soos, "Third-order NLO processes in polydiacetylenes: physics, materials, and devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices (Academic, New York, 1994), 433–465.

Sounik, J.

Stegeman, G. I.

S. Aramaki, W. Torruellas, R. Zanoni, and G. I. Stegeman, "Tunable third harmonic generation of trans-β–carotene," Opt. Commun. 85, 527–535 (1991).
[CrossRef]

V. Mizrahi, K. W. DeLong, G. I. Stegeman, M. A. Saifi, and M. J. Andrejco, "Two-photon absorption as a limitation to all-optical switching," Opt. Lett. 14, 1140–1142 (1989).
[CrossRef] [PubMed]

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Takagi, Y.

Tan, A.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Teng, C. C.

C. C. Teng and A. F. Garito, "Dispersion of the second-order optical susceptibility of organic systems," Phys. Rev. B 28, 6766–6773 (1983).
[CrossRef]

Tiemann, B. G.

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

S. R. Marder, C. B. Gorman, B. G. Tiemann, and L.-T. Cheng, "Stronger acceptors can diminish nonlinear optical response in simple donor-acceptor polyenes," J. Am. Chem. Soc. 115, 3006–3007 (1993).
[CrossRef]

S. R. Marder, C. B. Gorman, L.-T. Cheng, and B. G. Tiemann, "Optimizing the second-order optical nonlinearities of organic molecules: asymmetric cyanines and highly polarized polyenes," in Nonlinear Optical Properties of Organic Materials V, D. J. Williams, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1775, 19–31 (1992).
[CrossRef]

Torruellas, W.

S. Aramaki, W. Torruellas, R. Zanoni, and G. I. Stegeman, "Tunable third harmonic generation of trans-β–carotene," Opt. Commun. 85, 527–535 (1991).
[CrossRef]

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Velez, M.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Wang, N. Q.

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

Wong, K. Y.

Wu, J. W.

Wu, M.

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

Yoshihara, K.

Yu, Y. Z.

Zamani-Khamari, O.

Q. L. Zhou, R. F. Shi, O. Zamani-Khamari, and A. F. Garito, "Negative third-order optical responses in squaraines," Nonlinear Opt. 6, 145–154 (1993).

Zamani-Khamiri, O.

Zanoni, R.

S. Aramaki, W. Torruellas, R. Zanoni, and G. I. Stegeman, "Tunable third harmonic generation of trans-β–carotene," Opt. Commun. 85, 527–535 (1991).
[CrossRef]

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

Zhou, Q. L.

Q. L. Zhou, R. F. Shi, O. Zamani-Khamari, and A. F. Garito, "Negative third-order optical responses in squaraines," Nonlinear Opt. 6, 145–154 (1993).

Zyss, J.

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

Appl. Phys. Lett. (1)

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "20-fold pulse compression in a synchronously pumped optical parametric oscillator," Appl. Phys. Lett. 65, 1614–1616 (1994).
[CrossRef]

Chem. Mater. (2)

C. W. Dirk, H. E. Katz, M. L. Schilling, and L. A. King, "Use of thiazole rings to enhance molecular second-order nonlinear optical susceptibilities," Chem. Mater. 2, 700–705 (1990); "Errata," 3, 207 (1991).
[CrossRef]

C. W. Dirk and M. G. Kuzyk, "Squarilium dye-doped polymer systems as quadratic electrooptic materials," Chem. Mater. 2, 4–6 (1990).
[CrossRef]

Chem. Phys. (1)

R. W. Bigelow and H.-J. Freund, "An MNDO and CNDO/S(S+ DES CI) study of the structural and electronic properties of a model squaraine dye and related cyanine," Chem. Phys. 107, 159–174 (1986).
[CrossRef]

J. Am. Chem. Soc. (4)

C. W. Dirk, W. C. Herndon, F. Cervantes-Lee, H. Selnau, S. Martinez, P. Kalamegham, A. Tan, G. Campos, M. Velez, J. Zyss, I. Ledoux, and L.-T. Cheng, "Squarilium dyes: structural factors pertaining to the negative third-order nonlinear optical response," J. Am. Chem. Soc. 117, 2214–2225 (1995).
[CrossRef]

F. Meyers, S. R. Marder, B. M. Pierce, and J. L. Bredas, "Electric field modulated nonlinear optical properties of donor-acceptor polyenes: sum-over-states investigation of the relationship between molecular polarizabilities (α, β, and ϒ) and bond length alternation," J. Am. Chem. Soc. 116, 10703–10714 (1994).
[CrossRef]

S. R. Marder, J. W. Perry, B. G. Tiemann, S. Gilmour, S. L. Biddle, G. Bourhill, and C. B. Gorman, "Direct observation of reduced bond length alternation in donor/acceptor polyenes," J. Am. Chem. Soc. 115, 2524–2526 (1993).
[CrossRef]

S. R. Marder, C. B. Gorman, B. G. Tiemann, and L.-T. Cheng, "Stronger acceptors can diminish nonlinear optical response in simple donor-acceptor polyenes," J. Am. Chem. Soc. 115, 3006–3007 (1993).
[CrossRef]

J. Opt. Soc. Am. B (7)

C. Poga, T. M. Brown, M. G. Kuzyk, and C. W. Dirk, "Characterization of the excited states of a squaraine molecule with quadratic electroabsorption spectroscopy," J. Opt. Soc. Am. B 12, 531–543 (1995).
[CrossRef]

J. W. Wu, J. R. Heflin, R. A. Norwood, K. Y. Wong, O. Zamani-Khamiri, A. F. Garito, P. Kalyanaraman, and J. Sounik, "Nonlinear-optical processes in lower-dimensional conjugated structures," J. Opt. Soc. Am. B 6, 707–720 (1989).
[CrossRef]

K. D. Singer, J. E. Sohn, L. A. King, H. M. Gordon, H. E. Katz, and C. W. Dirk, "Second-order nonlinear-optical properties of donor- and acceptor-substituted aromatic compounds," J. Opt. Soc. Am. B 6, 1339–1350 (1989).
[CrossRef]

M. G. Kuzyk, J. E. Sohn, and C. W. Dirk, "Mechanisms of quadratic electro-optic modulation of dye doped polymer systems," J. Opt. Soc. Am. B 7, 842–858 (1990).
[CrossRef]

J. R. Heflin, Y. M. Cai, and A. F. Garito, "Dispersion measurements of electric-field-induced second-harmonic generation and third-harmonic generation in conjugated linear chains," J. Opt. Soc. Am. B 8, 2132–2147 (1991).
[CrossRef]

A. Agnesi, G. C. Reali, V. Kubecek, S. Kumazaki, Y. Takagi, and K. Yoshihara, "β-barium borate and lithium triborate picosecond parametric oscillators pumped by a frequencytripled passive negative-feedback mode-locked Nd:YAG laser," J. Opt. Soc. Am. B 10, 2211–2217 (1993).
[CrossRef]

J. D. V. Khaydarov, J. H. Andrews, and K. D. Singer, "Pulse-compression mechanism in a synchronously pumped optical parametric oscillator," J. Opt. Soc. Am. B 2199–2208 (1995).
[CrossRef]

Nonlinear Opt. (2)

J. H. Andrews, J. D. V. Khaydarov, K. D. Singer, D. L. Hull, and K. C. Chuang, "Spectral dispersion of third harmonic generation in squaraines," Nonlinear Opt. 10, 227 (1995).

Q. L. Zhou, R. F. Shi, O. Zamani-Khamari, and A. F. Garito, "Negative third-order optical responses in squaraines," Nonlinear Opt. 6, 145–154 (1993).

Opt. Commun. (1)

S. Aramaki, W. Torruellas, R. Zanoni, and G. I. Stegeman, "Tunable third harmonic generation of trans-β–carotene," Opt. Commun. 85, 527–535 (1991).
[CrossRef]

Opt. Lett. (4)

Phys. Rev. A (2)

M. G. Kuzyk and C. W. Dirk, "Effects of centrosymmetry on the nonresonant electronic third-order nonlinear optical susceptibility," Phys. Rev. A 41, 5098–5109 (1990).
[CrossRef] [PubMed]

J. R. Heflin, D. C. Rodenberger, R. F. Shi, M. Wu, N. Q. Wang, Y. M. Cai, and A. F. Garito, "Experimental observation of enhanced nonresonant nonlinear optical responses from optically pumped electronic excited states," Phys. Rev. A 45, R4233–R4236 (1992).
[CrossRef]

Phys. Rev. B (1)

C. C. Teng and A. F. Garito, "Dispersion of the second-order optical susceptibility of organic systems," Phys. Rev. B 28, 6766–6773 (1983).
[CrossRef]

Rev. Sci. Instrum. (1)

F. Kajzar and J. Messier, "Original technique for third-harmonic-generation measurements in liquids," Rev. Sci. Instrum. 58, 2081–2085 (1987).
[CrossRef]

Science (1)

S. R. Marder, J. W. Perry, G. Bourhill, C. B. Gorman, B. G. Tiemann, and K. Mansour, "Relation between bond-length alternation and second electronic hyperpolarizability of conjugated organic molecules," Science 261, 186–189 (1993).
[CrossRef] [PubMed]

Solid State Commun. (1)

F. Kajzar, S. Etemad, G. L. Baker, and J. Messier, "Frequency dependence of the large, electronic x(3) in polyacetylene," Solid State Commun. 63, 1113–1117 (1987).
[CrossRef]

Other (7)

Optical Glass, Schott Glass Technologies Inc. catalog (Schott Glass, Duryea, Pa., 1990).

C. Poga, M. G. Kuzyk, S. Martinez, and C. W. Dirk, "Quadratic electroabsorption spectroscopy as a probe of x(3) mechanisms in dye-doped polymers," in Nonlinear Optical Properties of Organic Materials VI, G. R. Moehlmann, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 2025, 363–372 (1993).
[CrossRef]

B. M. Pierce, "A theoretical analysis of the third-order nonlinear optical properties of linear cyanines and polyenes," in Nonlinear Optical Properties of Organic Materials IV, K. D. Singer, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1560, 148–161 (1991).
[CrossRef]

K. D. Singer and J. H. Andrews, "Quadratic nonlinear optics in poled polymer films: From physics to devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices, J. Zyss, ed. (Academic, New York, 1994), pp. 245–298.

D. Guo, S. Mazumdar, G. I. Stegeman, M. Cha, D. Neher, S. Aramaki, W. Torruellas, and R. Zanoni, "Nonlinear optics of linear conjugated polymers," in Vol. 247 of Symposium Proceedings of the Materials Research Society (Materials Research Society, Pittsburgh, Pa., 1992), pp. 151–162.
[CrossRef]

S. Etemad, G. L. Baker, and Z. G. Soos, "Third-order NLO processes in polydiacetylenes: physics, materials, and devices," in Molecular Nonlinear Optics: Materials, Physics, and Devices (Academic, New York, 1994), 433–465.

S. R. Marder, C. B. Gorman, L.-T. Cheng, and B. G. Tiemann, "Optimizing the second-order optical nonlinearities of organic molecules: asymmetric cyanines and highly polarized polyenes," in Nonlinear Optical Properties of Organic Materials V, D. J. Williams, ed., Proc. Soc. Photo-Opt. Instrum. Eng. 1775, 19–31 (1992).
[CrossRef]

Cited By

OSA participates in CrossRef's Cited-By Linking service. Citing articles from OSA journals and other participating publishers are listed here.

Alert me when this article is cited.


Figures (13)

Fig. 1
Fig. 1

Structure of bis(4-aminophenyl) squaraine (SQR) studied theoretically by Zhou et al.15 Their calculated values for the excited-state energies and transition moment strengths are consistent with our experimental results for other squaraines described in Section 3, except with respect to the strength of the μ12 transition.

Fig. 2
Fig. 2

Chemical structures of squaraine dyes ISQ, C16-ISQ, C16-ThSQ, and C16-ISQ-BSQ.

Fig. 3
Fig. 3

Linear absorption spectra of ISQ (solid curve) and C16-ISQ (dashed curve) in chloroform. For ISQ, the peak molar absorptivity in chloroform is M = 175,000 ± 10,000 M−1 cm−1. For C16-ISQ, M = 310,000 ± 10,000 M−1 cm−1.

Fig. 4
Fig. 4

Linear absorption spectra of C16-ThSQ (solid curve) and C16-ISQ-BSQ (dashed curve) in chloroform. For C16-ThSQ, the peak molar absorptivity in chloroform is M = 280,000 ± 10,000 M−1 cm−1. For C16-ISQ-BSQ, M = 250,000 ± 25,000 M−1 cm−1.

Fig. 5
Fig. 5

Spectral wavelength ranges for third-harmonic dispersion experiments, where arrows show the scanned fundamental, third-harmonic, and intermediate wavelengths. The squaraine dye linear absorption spectra (to 800 nm) are shown for reference. Radiation at the third harmonic was detected for the indicated range of fundamental wavelengths, allowing us to probe the intermediate 2ω resonances through the resonant denominators in Eq. (3).

Fig. 6
Fig. 6

Experimental geometry used for third-harmonic generation. PMT’s, photomultiplier tubes; ovals show focusing lenses.

Fig. 7
Fig. 7

Typical Maker fringes obtained from third-harmonic generation on low-concentration solutions of squaraine dyes in chloroform.

Fig. 8
Fig. 8

Ratio of the third-harmonic fringe amplitudes of 0.215 ± 0.02% ISQ in chloroform to the fringe amplitudes of pure chloroform. Errors were estimated from only the uncertainties in the measured Maker fringe amplitudes that were due to absorption of the third harmonic. The solid curve is a four-level fit obtained with the parameters listed in Table 1, with level diagrams for the relevant virtual transitions shown schematically in the inset.

Fig. 9
Fig. 9

Ratio of the third-harmonic fringe amplitudes of 0.46 ± 0.02% C16-ISQ by weight in chloroform to the fringe amplitudes of pure chloroform. Errors were estimated from only the uncertainties in the measured Maker fringe amplitudes that were due to absorption of the third harmonic. The solid curve is a four-level fit obtained with the parameters listed in Table 1, with level diagrams for the relevant virtual transitions shown schematically in the inset.

Fig. 10
Fig. 10

Ratio of the third-harmonic fringe amplitudes of 0.43 ± 0.02% C16-ThSQ by weight in chloroform to the fringe amplitudes of pure chloroform. Errors were estimated from only the uncertainties in the measured Maker fringe amplitudes that were due to absorption of the third harmonic. The solid curve is a modified four-level fit obtained with the three-level parameters listed in Table 2, with level diagrams for the relevant transitions and the transitions to a weak additional Bu level shown in the inset. This additional Bu level was needed to account for the effect of the ultraviolet absorption below 400 nm, as described in the text.

Fig. 11
Fig. 11

Ratio of the third-harmonic fringe amplitudes of 0.33 ± 0.04% C16-ISQ-BSQ by weight in chloroform to the fringe amplitudes of pure chloroform. Errors were estimated from only the uncertainties in the measured Maker fringe amplitudes that were due to absorption of the third harmonic. The solid curve is a modified four-level fit obtained with the three-level parameters listed in Table 2, with level diagrams for the relevant transitions shown in the inset.

Fig. 12
Fig. 12

Predicted optical Kerr effect γ(−ω; ω, ω, −ω) for ISQ (solid curve, real part; dashed curve, imaginary part; dotted curve, their ratio) obtained with the fit parameters from Table 1 for ISQ in chloroform.

Fig. 13
Fig. 13

Predicted optical Kerr effect γ(−ω; ω, ω, −ω) for C16-ISQ (solid curve, real part; dashed curve, imaginary part; dotted curve, their ratio) obtained with the fit parameters from Table 1 for C16-ISQ in chloroform.

Tables (2)

Tables Icon

Table 1 Four-Level Fit Parameters for Dispersion of Third Harmonic of 0.215 ± 0.02% ISQ and 0.46 ± 0.02% C16-ISQ by Weight in Chloroform

Tables Icon

Table 2 Four-Level Fit Parameters for Dispersion of Third Harmonic of 0.43 ± 0.02% C16-ThSQ and 0.33 ± 0.04% C16-ISQ-BSQ by Weight in Chloroform

Equations (13)

Equations on this page are rendered with MathJax. Learn more.

β x x x ( - 2 ω ; ω , ω ) = μ 01 2 Δ μ 10 2 2 F 11 ( ω ) ,
F 11 = [ ( Ω 10 - 2 ω ) ( Ω 10 - ω ) ] - 1 + [ ( Ω 10 * + ω ) ( Ω 10 * + 2 ω ) ] - 1 + [ ( Ω 10 * + ω ) ( Ω 10 - ω ) ] - 1 .
γ x x x x ( - 3 ω ; ω , ω , ω ) = μ 01 2 4 3 [ Δ μ 10 2 D 111 - μ 01 2 D 11 + ( n μ 1 n 2 D 1 n 1 ) ] ,
D l m n = [ ( Ω n 0 - ω ) ( Ω m 0 - 2 ω ) ( Ω l 0 - 3 ω ) ] - 1 + [ ( Ω n 0 * + ω ) ( Ω m 0 - 2 ω ) ( Ω l 0 - ω ) ] - 1 + [ ( Ω n 0 * + ω ) ( Ω m 0 * + 2 ω ) ( Ω l 0 - ω ) ] - 1 + [ ( Ω n 0 * + ω ) ( Ω m 0 * + 2 ω ) ( Ω l 0 * + 3 ω ) ] - 1 ,
D l n = [ ( Ω l 0 - ω ) ( Ω l 0 - 3 ω ) ( Ω n 0 - ω ) ] - 1 + [ ( Ω l 0 * + ω ) ( Ω l 0 - ω ) ( Ω n 0 - ω ) ] - 1 + [ ( Ω l 0 - ω ) ( Ω l 0 * + ω ) ( Ω n 0 * + ω ) ] - 1 + [ ( Ω l 0 * + ω ) ( Ω l 0 * + 3 ω ) ( Ω n 0 * + ω ) ] - 1 .
D 1 n 1 [ ( ω 10 - 3 ω - i Γ 10 ) ( ω n 0 - 2 ω - i Γ n 0 ) × ( ω 10 - ω - i Γ 10 ) ] - 1 ,
D 111 [ ( ω 10 - 3 ω - i Γ 10 ) ( ω 10 - 2 ω - i Γ 10 ) × ( ω 10 - ω - i Γ 10 ) ] - 1 ,
D 11 [ ( ω 10 - 3 ω - i Γ 10 ) ( ω 10 - ω - i Γ 10 ) × ( ω 10 - ω - i Γ 10 ) ] - 1 .
μ 01 = [ ( ν d ν ν 01 ) 3 ln ( 10 ) h c 0 2 π 2 N A ] 1 / 2 ,
A ¯ thg L A ¯ thg R = ( T G L / Δ n G 2 ) χ G ( 3 ) - ( T L / Δ n L 2 ) χ L ( 3 ) ( t ω L ) 3 2 [ ( T G R / Δ n G 2 ) χ G ( 3 ) - ( T R / Δ n R 2 ) χ R ( 3 ) ( t ω R ) 3 ] 2 ,
t ω X = 2 n ω G n ω G + n ω X ,             T X = n ω X + n 3 ω X n 3 ω G + n 3 ω X , T G X = n ω G + n 3 ω X n 3 ω G + n 3 ω X .
χ L ( 3 ) m chloroform m total χ R ( 3 ) + ( f ω ) 3 f 3 ω N γ + i γ d ye ,
D 121 Kerr [ ( ω 10 - ω - i Γ 10 ) ( ω 10 - ω + i Γ 10 ) × ( ω 20 - 2 ω - i Γ 20 ) ] - 1 .

Metrics