Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9786184 | Optics Communications | 2005 | 8 Pages |
Abstract
We present all-optical switching in Zinc (II) tetraphenylporphyrin (ZnTPP) and Vanadium (IV)-oxide tetraphenylporphyrin (VOTPP) using pump probe method. A cw probe laser beam of 633 nm passing through the dye solutions is switched by a 20-ns pulsed pump laser beam of 532 nm. Our results show that there is an optimum value of concentration of the medium for which maximum modulation of the probe beam can be achieved. Probe beam modulation saturates after a certain value of pump intensity. Switch 'off' and 'on' time for VOTPP are â¼1.5 and â¼2.5 μs, respectively and for ZnTPP, respective times are â¼200 ns and â¼3.5 μs. Experimental results have been explained by doing a theoretical analysis based on nonlinear intensity induced excited state absorption using the rate equation model. Our analysis indicates that in VOTPP the long switch off time could be due to the existence of an intermediate state between the first singlet and triplet state.
Related Topics
Physical Sciences and Engineering
Materials Science
Electronic, Optical and Magnetic Materials
Authors
C.P. Singh, K.S. Bindra, B. Jain, S.M. Oak,