χ (3) measurements and optical limiting in dibenzylideneacetone and its derivatives

• Published in: Chemical physics Vol. 324; no. 2; pp. 699 - 704
• Main Authors: Kiran, A. John, Chandrasekharan, K., Nooji, Satheesh Rai, Shashikala, H.D., Umesh, G., Kalluraya, Balakrishna
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31-05-2006
• Subjects: Nonlinear absorption; Nonlinear optics; Nonlinear refraction; Optical limiting; Optical susceptibility; Z-scan; Optical limiting; Nonlinear absorption; Z-scan; Nonlinear optics; Nonlinear refraction; Optical susceptibility
• ISSN: 0301-0104
• DOI: 10.1016/j.chemphys.2005.12.006

We investigated the third order nonlinear optical properties of dibenzylidene acetone (1,5-diphenyl-1, 4-pentadeine-3-one) and its derivatives. The nonlinear measurements were performed by using single beam Z-scan technique with Q-switched Nd:YAG nanosecond laser pulses at 532
nm. Open aperture data for dibenzylidene and its derivatives demonstrate the presence of two-photon absorption at this wavelength. The dependence of
χ
(3) on donor/acceptor type substituents to the basic compound clearly shows the electronic origin of nonlinearity and hence demonstrates that the mechanism by which the third order nonlinear response enhanced is not by the thermal effects, but instead due to the strong nonlinear absorption and nonlinear refraction of the compounds. The derivatives of the basic compound show very good optical limiting behavior.