Molecular-length dependence of third-order nonlinear optical properties in conjugated organic materials

Kanbara, Hirohisa; Kobayashi, Hideki; Kaino, Toshikuni; Ooba, Naoki; Kurihara, Takashi

doi:10.1021/j100098a024

Cited by 8 publications

(10 citation statements)

References 10 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…Deviations from the power law ͑1͒ were also observed by others. 76,77 Furthermore, we see that the ͑3͒ data of several conjugated -electron systems which have max in the range between 450 and 500 nm can scatter over more than two orders of magnitude. This can lead to doubts as to whether a general scaling between linear and nonlinear optical properties exists at all.…”

Section: B Masterplot Of Third-order Nonlinearities For One-dimensiomentioning

confidence: 83%

Third-harmonic-generation spectroscopy of poly(p-phenylenevinylene): A comparison with oligomers and scaling laws for conjugated polymers

et al. 1996

View full text Add to dashboard Cite

The third-order nonlinear optical susceptibility ͑3͒ ͑Ϫ3;,,͒ of thin films of poly͑p-phenylenevinylene͒ ͑PPV͒ and several corresponding oligomers ͑OPV-n͒ has been investigated by third-harmonic generation using variable laser wavelengths from 900 to 1520 nm. The oligomers show a single three-photon resonance of ͑3͒ ͑Ϫ3;,,͒ which is closely related to the linear absorption spectrum. We can identify, however, two maxima in the ͑3͒ spectrum of PPV. They are assigned to three-photon resonances with the maximum of the exciton absorption and with the threshold of the continuum of states, which can be located at 3.2Ϯ0.1 eV. This corresponds to an exciton binding energy of 0.7Ϯ0.1 eV. We observe a general scaling behavior for PPV, OPV-n, and other one-dimensional conjugated -electron systems in their neutral form. Their ͑3͒ values, evaluated at comparable resonant or low-resonant conditions, follow an empirical scaling relationship(3) /␣ max ϳ max x , where ␣ max and max denote the absorption coefficient and wavelength of the low-energy absorption maximum. We obtain an exponent xϭ10Ϯ1 which is much larger than expected from an earlier theory. Possible reasons for the difference between theory and experimental results are discussed.

show abstract

Section: B Masterplot Of Third-order Nonlinearities For One-dimensiomentioning

confidence: 83%

Third-harmonic-generation spectroscopy of poly(p-phenylenevinylene): A comparison with oligomers and scaling laws for conjugated polymers

et al. 1996

View full text Add to dashboard Cite

show abstract

“…For conjugated systems, as a general rule, the larger the conjugation length along the main polymer chain, the more intense the third-order nonlinear response, and the nonlinear refractive index exhibits a power-law dependence. [14,15] Of course, this implies, as a necessary (but not sufficient) condition, that the polymer have long, regioregular chains.…”

Section: Optical Propertiesmentioning

confidence: 99%

Non‐Resonant z‐Scan Characterization of the Third‐Order Nonlinear Optical Properties of Conjugated Poly(thiophene azines)

et al. 2008

View full text Add to dashboard Cite

The nonlinear optical properties of a functionalized poly(thiophene azine), namely, poly(3,4-didodecylthiophene azine), PAZ, at the optical telecommunication wavelength of 1550 nm are investigated by means of the closed-aperture z-scan technique in both thin films and solutions. Values of chi((3))=(2.4+/-0.4)x10(-13) esu, n(2)=(4.0+/-0.7)x10(-15) cm(2) W(-1), and gamma=(4.5+/-0.7)x10(-34) esu are estimated for the third-order (Kerr) susceptibility, the intensity-dependent refractive index, and the molecular second hyperpolarizability of solution samples, respectively. A very small dependence on the polymer chain length is found. Markedly higher values of (4.4+/-1.1)x10(-11) esu, (6.6+/-1.0)x10(-13) cm(2) W(-1), and (5.0+/-0.8)x10(-33) esu are measured for the corresponding quantities in thick (up to 20 mum) polymer films cast on quartz plates. The enhancement of the NLO responses on going from solution to solid samples is attributed to a partially ordered structure and to the presence of interchain interactions leading to greater pi-electron delocalization in the cast polymer films. The results are compared with those previously obtained by using third-harmonic generation (THG), taking into account that those data were measured under conditions of three-photon resonance, whereas our z-scan measurements are fully off-resonance.

show abstract

“…The nonlinear refractive index n 2 (THG), which is defined in terms of self-phase modulation (SPM), , was derived from the THG measurement. The difference-frequency generator consisting of a LiNbO 3 crystal provided a pump beam with a wavelength from 1.5 to 2.2 μm.…”

Section: Methodsmentioning

confidence: 99%

“…The pump power density was varied from 50 to 100 MW/cm 2 . The THG nonlinearity n 2 (THG) was calculated by comparing the TH intensity with the standard of fused silica glass. − The n 2 (THG) value is given by where n is the linear refractive index, l c is the coherence length, and I 3 ω is the TH intensity. The subscript s indicates the standard medium.…”

Section: Methodsmentioning

confidence: 99%

High-Speed Third-Order Nonlinear Optical Response Using Organic Solutions

Kanbara¹,

Fujiwara²,

Tanaka³

et al. 1998

J. Phys. Chem. A

Self Cite

View full text Add to dashboard Cite

We have observed high-speed third-order nonlinear optical response using organic solutions of π-conjugated low-molecular-weight compounds. Optical Kerr shutter (OKS) measurement, third-harmonic generation (THG) measurement, and a degenerate four-wave mixing (DFWM) experiment were carried out to examine the high-speed response in several organic solutions. A comparison between the OKS and THG nonlinearities indicates that a long molecule increases the ratio of the fast electronic contribution in the all-Kerr nonlinearity. The fast response characteristics are confirmed by the DFWM experiment, thus showing that a long molecule successfully reduces the contribution of the molecular orientation effect with a slow relaxation time.

show abstract

Molecular-length dependence of third-order nonlinear optical properties in conjugated organic materials

Cited by 8 publications

References 10 publications

Third-harmonic-generation spectroscopy of poly(p-phenylenevinylene): A comparison with oligomers and scaling laws for conjugated polymers

Third-harmonic-generation spectroscopy of poly(p-phenylenevinylene): A comparison with oligomers and scaling laws for conjugated polymers

Non‐Resonant z‐Scan Characterization of the Third‐Order Nonlinear Optical Properties of Conjugated Poly(thiophene azines)

High-Speed Third-Order Nonlinear Optical Response Using Organic Solutions

Contact Info

Product

Resources

About