Photoacoustic investigations on the photostability of Coumarin 540-doped PMMA.
In this paper, we present a laser-induced photoacoustic study on the photostability of laser dye Coumarin 540 doped in PMMA matrix and modified by the incorporation of low-molecular weight additives. The dependence of photostability of the dye on various experimental conditions, such as nature of solvents, incident optical power and dye concentration, is investigated in detail. The activation rates for the bleaching process are calculated for different concentrations and they suggest the possibility of two distinct mechanisms responsible for photodegradation. Further, analysis of the data confirms the linear dependence of photodegradation on the intensity of incident radiation. The role of different externally influencing parameters, such as wavelength and modulation frequency of incident radiation, is also discussed.
Nedumpara
Ritty J
RJ
International School of Photonics, Cochin University of Science and Technology, Cochin 680222, Kerala, India. rtnedumpara@cusat.ac.in
Paul
Binoy
B
Santhi
A
A
Radhakrishnan
P
P
Nampoori
V P N
VP
D000162:Acoustics; D003374:Coumarins / Q000737:chemistry*; D007834:Lasers; D008027:Light; D008956:Models, Chemical; D011108:Polymers; D019904:Polymethyl Methacrylate / Q000737:chemistry*; D013053:Spectrophotometry / Q000379:methods*; D013997:Time Factors
D003374:Coumarins; D011108:Polymers; D019904:Polymethyl Methacrylate; C030123:coumarin