Dispersion of the nonlinear absorption of copper phthalocyanine in a silica xerogel matrix through the visible spectrum

Recently, macrocyclic organic dyes have attracted a lot of attention as possible candidates for applications in optical power limiters and pulse shaping devices. We present results for the effective excited state absorption cross section of copper phthalocyanine tetrasulfonate (CuPcTs) in a CuPcTs/Silica xerogel composite. The sample was prepared by the sol-gel method using ultrasound energy to promote the hydrolysis of tetramethoxysilane which was the silica precursor. The study has been performed in the visible region of the spectrum from 450 to 730 nm. This study represents a complete description of the dispersion of the nonlinear absorption for the composite. Measurements were also obtained for a solution of the CuPc in sulfuric acid for comparison purposes. We observed reverse saturable absorption in the range of 450-540 nm wavelength and saturable absorption in the range 570-730 nm wavelength for the composite. (C) 1998 American Institute of Physics.