RELATIONSHIP BETWEEN GROWTH RATE OF LASER-INDUCED DAMAGE IN POLYALKYLMETHACRYLATES AND THEIR GLASS TRANSITION TEMPERATURE

The interaction of laser light with the transparent organic high polymers with Q-switching dye was investigated. Several sorts of polyalkylmethacrylate plates, for which glass transition temperature was a function of composition of copolymers made of methylmethacrylate and n-butylmethacrylate, were prepared, and the relationship between the growth rate of the laser-induced damage and the thermal properties was examined. When the ambient temperature of these copolymer plates was 27°C, the growth rate of the damage becomes slower with the decrement of their glass transition temperature. The authors found that the difference (Tg-T) or the ratio (Tg/T) of glass transition temperature (Tg) and ambient temperature (T) of the organic high polymers exerts predominant influence on the growth rate of laser-induced damage. © 1969 The American Institute of Physics.