Limitation of optical radiation power by organic molecules: II. Porphyrins and phthalocyanines

The nonlinear transmission of high-power 532-nm and 308-nm laser pulses of duration 7–13 ns by solutions of porphyrins and phthalocyanines and their metal complexes (13 compounds) is studied. The limitation of optical radiation at wavelengths 532 and 308 nm is studied depending on the laser radiation intensity, the solvent type, and the concentration of solutions. The effective cross sections for absorption of radiation by excited molecules are estimated. The induced short-lived absorption in the visible spectral region is studied in the range of hundreds of nanoseconds. The mechanisms of limitation of laser radiation are discussed.