Study on nonlinear optical absorption properties of [(CH 3) 4N] 2[Cu(dmit) 2] by Z-scan technique

• Published in: Optics and laser technology 2009, Vol.41 (2), p.209-212
• Main Authors: Sun, Jing, Ren, Quan, Wang, Xin-Qiang, Zhang, Guang-Hui, Xu, Dong
• Format: Article
• Language: English
• Subjects: Beam trapping, self-focusing and defocusing; self-phase modulation; Exact sciences and technology; Fundamental areas of phenomenology (including applications); Metallo-organics; Nonlinear absorption; Nonlinear optical crystals; Nonlinear optics; Optical materials; Optical susceptibility, hyperpolarizability; Optics; Physics; Z-scan technique
• ISSN: 0030-3992; 1879-2545
• DOI: 10.1016/j.optlastec.2008.05.010

The third-order optical nonlinearities of an organo-metallic compound, [(CH 3) 4N] 2[Cu(dmit) 2] (dmit 2−=4,5-dithiolate-1,3-dithiole-2-thione), abbreviated as MeCu, dissolved in acetone are characterized by Z-scan technique with picosecond and nanosecond laser pulses in the near-infrared region. Two-photon absorption has been found when the sample solution is irradiated by 40 ps pulse width at 1064 nm and the two-photon absorption (TPA) coefficient β TPA is 4×10 −13 m/W. While excited by 15 ns laser pulses at 1053 nm, the Z-scan spectra reveal strong reverse saturable absorption (RSA) and the nonlinear absorption coefficient β RSA is estimated to be as high as 7.07×10 −11 m/W which is much larger than β TPA. An explanation for this enhancement is given. All the results suggest that MeCu may be a promising candidate for the application to optical limiting in the near-infrared region.