论文信息 - Optical nonlinearities of (TBA)2Ni(dmit)2: saturable-absorption and negative third-order nonlinear refraction due to charge-transfer transition

Optical nonlinearities of (TBA)2Ni(dmit)2: saturable-absorption and negative third-order nonlinear refraction due to charge-transfer transition

The optical nonlinearity of (TBA)2Ni(dmit)2 (TBA = tert-n-butanyl-amonimium, dmit = 1,3-dithiol-2-thione-4,5-dithiolate) at high incident irradiance was investigated using Z-scan technique with 1064 nm picosecond laser pulses. This molecule shows a strong absorption band ranging from 900 to 1600 nm. Under excitation by 1064nm laser pulses, this molecule exhibits typical saturable-absorption (SA) due to this transition, and shows a negative third-order contribution to nonlinear refraction (NLR). This result indicates that it shows a third-order self-defocusing. In addition, a positive fifth-order contribution to NLR, and the influences of aggregation and high excited-state absorption on nonlinear absorption were also observed in this molecule.

[1] Lei Zhang,et al. Nonlinear excited state absorption in cadmium texaphyrin solution , 1994 .

[2] Brian S. Wherrett,et al. The saturation limit to picosecond, induced absorption in dyes , 1993 .

[3] Christopher M. Lawson,et al. Characterization of the third-order nonlinearity of [(CH3-TXP)Cd]Cl , 1999, Optics & Photonics.

[4] Deqing Zhang,et al. Three-photon absorption from six stilbazolium derivatives: application for optical limiting , 2002 .

[5] A. Kobayashi,et al. The First Molecular Superconductor Based on π-Acceptor Molecules and Closed-Shell Cations, [(CH3)4N][Ni(dmit)2]2, Low-Temperature X-Ray Studies and Superconducting Transition , 1987 .

[6] F. Kaufman,et al. Optical properties of charge transfer salts of tetracyanoquinodimethane (TCNQ) , 1993 .

[7] Mansoor Sheik-Bahae,et al. Determination of bound-electronic and free-carrier nonlinearities in ZnSe, GaAs, CdTe, and ZnTe , 1992 .

[8] R R Alfano,et al. Excited-state nonlinearity in polythiophene thin films investigated by the Z-scan technique. , 1992, Optics letters.

[9] Wenfang Sun,et al. Degenerate four-wave mixing and Z-scan measurements of stilbazolium derivatives , 2001 .

[10] Daoben Zhu,et al. Third- and fifth-order optical nonlinearities in a new stilbazolium derivative , 2002 .