Excited-state absorption spectroscopy of metallo-porphyrin dyes with both Q- and B-band excitation

Summary form only given. Optical limiting based on reverse-saturable absorber (RSA) dyes has been the subject of extensive investigation in recent years. In particular, we have been studying metallophthalocyanine and metallo-porphyrine derivatives, both of which have strong absorption bands in the red/near-infrared (Q-band) and the blue/ultraviolet (B-band) spectral regions. With picosecond pulses, strong excited-state absorption (ESA) is observed from the bottom of this manifold. The strong RSA exhibited by these materials at 532 nm prompted us to study the excited-state absorption and refraction at other wavelengths throughout the visible.