All-optical switching characteristics of ethyl red doped polymer film

The azo dye ethyl red (ER) doped methyl methacrylate (PMMA) polymer films were prepared by the sol–gel process and the repeat-spin-coating method, the all-optical switching characteristics of the film samples were investigated experimentally at different intensities and modulation frequencies of pump beam (532 nm, CW), and the influence of the doping concentrations and the solvents on the all-optical switching effect of the films was discussed. At low pump power (8 mW), the modulation depth of 50% was obtained and the response time was near 1 ms at room temperature. Furthermore, the maximal modulation depth reaches 72%. An excellent switching performance could be obtained by choosing the proper doping concentrations (from 2 wt% to 6 wt%) of the samples, and the switching characteristics of the samples can be improved using cyclohexanone solvent. The experimental results show that ER-doped polymer has potential application in optical switching.