Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10560891 | Talanta | 2005 | 7 Pages |
Abstract
A composite optical waveguide (OWG) composed of a 10-18Â nm thick titanium dioxide (TiO2) film sputtered on a conventional K+-doped optical waveguide was first applied to detect transient absorption of organic dyes in ultrathin polymer films upon excitation with ns laser. The thickness of the TiO2 film considerably affected the relative sensitivity of the composite OWG. The composite OWG with 10Â nm thick TiO2 gave much stronger transient absorption for 30-415Â nm thick polymer films containing organic dyes than that with 18Â nm TiO2. Transient absorption of phthalocyanine and spiropyran in 20-135Â nm thick polymer films was detected 3-20 times more sensitively by the composite OWG with 10Â nm TiO2 than the conventional K+-doped OWG which showed a 150-fold sensitivity as compared with the usual normal incidence method. The relative sensitivity of the composite waveguide was also affected by the thickness and refractive index of polymers.
Keywords
Related Topics
Physical Sciences and Engineering
Chemistry
Analytical Chemistry
Authors
Toshihiko Nagamura, Tatsuo Adachi, Kyoichi Sasaki, Hideki Kawai, Xiao-Min Chen, Kiminori Itoh, Masayuki Murabayashi,