We report on our investigations of the third order optical properties of two novel prophyrin dimers and their optical limiting behaviors. Our experiments were performed by using single beam z-scan technique and with Q-switched Nd: YAG nanosecond laser pulses at 532nm and CW laser at 532nm respectively for two different optical limiting mechanisms, strong excited state absorption (ESA) and thermal self-defocusing. In the experiments with pulsed laser, the open aperture results indicated that the two dimers showed strong excited state absorption which occurs when the excited state has an absorption cross-section higher than that of ground state. In the experiments with CW laser, optical limiting behaviors have also been observed. In this case, the third order optical nonlinearitiy is caused by thermal self-defocusing mechanism. Our results indicated that both novel prophyrin dimers showed potential use in optical limiters, optical switches and optical modulators.

Date Published: 4 January 2008
PDF: 5 pages
Proc. SPIE 6839, Nonlinear Optics: Technologies and Applications, 683903 (4 January 2008); doi: 10.1117/12.759633

Published in SPIE Proceedings Vol. 6839:
Nonlinear Optics: Technologies and Applications
Yiping Cui; Qihuang Gong; Yuen-Ron Shen, Editor(s)