Optical transmittance of carbon suspensions in polymer matrixes under powerful pulsed laser irradiation

Abstract

The effect of optical limiting is investigated in the suspensions of carbon microparticles in aqueous gelatin gel and epoxy resin. Both transient and permanent changes of optical transmittance are observed after the irradiation by a Q-switched YAG:Nd³⁺ laser pulses. The experimental results are explained with taking into account the formation of micro-bubbles filled with water steam and with gaseous products of decomposition of the matrix. In the epoxy resin suspensions, the laser-induced permanent changes of transmittance are caused by pyrolysis of epoxy oligomers in the vicinity of laser-heated carbon particles.