Synthesis, theoretical modeling and characterization of optical limiting materials

The "Photonics in defense applications" program is a collaboration between FOI, Universities and industries in Sweden. One of the projects within this program is "Technical demonstration of electro-optical counter counter-measures." The goal for this 3-year project is to incorporate protective devices within a model sight with the aim to protect the human eye against laser damage. This report gives a short introduction to the project and summarizes the results obtained on passive optical limiters during the first project year. The optical limiting performance of the compounds was investigated with the dyes in solution. The solutions were prepared with a photopic transmission of approximately 70%. Eleven new compounds were investigated. The investigations were performed with a frequency doubled Nd:YAG delivering 5 ns pulses at 532 nm. A tunable laser with an optical parametric oscillator (OPO) was also used to perform measurements at various wavelengths. A f/5 arrangement was used in the experiments. A mixture of alkynylplatinum(II), with a photopic transmission of 68%, gave the best result; clamping values <1 mikroJ were observed for a major part of the visible wavelengths.