Photobleaching of Cresyl Violet in poly(methyl methacrylate)
Abstract
This study investigates the rapidity with which an optical dye in a solid plastic host irreversibly degrades when it is brightly illuminated by visible light. Specifically, the organic dye cresyl violet perchlorate dispersed in plexiglas was optically excited by a continuous-wave dye laser pumped by an argon-ion laser. After resonantly absorbing and emitting many times, an individual dye molecule photochemically bleaches. The decay of the overall fluorescence signal was measured and fit to a theoretical model describing the time dependence of the bleaching in terms of a quantum efficiency for photooxidation. Under ambient conditions, it takes a few million excitation-relaxation cycles to bleach a dye molecule at incident intensities on the order of 100 W/cm2. This permanently destroys the dye, thereby limiting applications of such organic materials under exposure to high optical intensities, in laser sensors or fibers, for example.
Document Details
- Document Type
- Technical Report
- Publication Date
- May 01, 2004
- Accession Number
- ADA640878
Entities
People
- Carl E. Mungan
- Michael J. Holmes