Michael E. Boyle

THIRD-ORDER NONLINEAR OPTICAL PROPERTIES OF METALLO-PHTHALOCYANINES

This paper discusses the third-order nonlinear optical (NLO) properties of metal-free, lead and transition metal phthalocyanines, as well as scandium, yttrium and lanthanide bisphthalocyanines measured by time-resolved degenerate four-wave mixing at 1064 nm. The study focuses on the structure-property relationships and explores the possible mechanisms leading to the enhanced third-order optical nonlinearity measured for this interesting class of NLO materials.

Lead phthalocyanine reverse saturable absorption optical limiters

Systematic studies of the nonlinear optical properties of organic materials have led to the development of promising new materials for optical limiting. Several heavy metal substituted phthalocyanines are effective materials for optical limiters in the visible and near IR. Nonlinear absorption is the principal mechanism near the limiting threshold. In fast optical systems, refractive contributions also contribute at higher energies. These refractive contributions are predominantly thermal. The spectral window over which the limiter operates can be engineered by altering both the main ring and peripheral substitution of the molecules.

Optical Limiting in Phthalocyanine Solutions and in Pure Liquid Phthalocyanines

Optical limiting, degenerate four-wave mixing and transient absorption experiments have been performed on a neat liquid lead substituted phthalocyanine. The photophysical mechanisms responsible for the good optical limiting observed in other phthalocyanine solutions are maintained in this pure liquid despite its different peripheral substitution pattern. The liquid is shown to have excited state absorption cross sections that exceed those of the ground state through much of the visible spectrum. Hybrid absorptive/refractive nonlinear response is demonstrated to contribute to both the four-wave mixing and optical limiting response. The mechanism and states responsible are discussed.

Vacuum ultraviolet MCD and absorption spectra of benzene isolated in an Ar matrix using synchrotron radiation

Abstract The 1 B 1u 1 E 1u valence and 2R Rydberg states of benzene isolated in Ar matrices have been studied using synchrotron radiation. The 1E 1u MCD A term is positive as in solution. Various features of the condensed and vapor phase MCD are rationalized in light of the large Ar matrix blue-shift of the 2R Rydberg state.

Excited state absorption and dynamics in a Pb-phthalocyanine copolymer

Transient absorption and degenerate four-wave mixing measurements on a thin film Pb- phthalocyanine-urethane-butanediol copolymer show that this material has a strong excited state absorption in the visible and near-IR. The excited state absorption cross section, (sigma) ex, exceeds that of the ground state, (sigma) g from 430 to 620 nm and at 1064 nm. DFWM measurements at 590 nm show both an instantaneous response ((tau) < 1 ps) and a long lived response from an excited state with a rise time of less than 1 ps, and a decay time of > 10 ns.

Vacuum ultraviolet MCD and absorption spectra of zinc phthalocyanine isolated in an Ar matrix using synchrotron radiation

Abstract The magnetic circular dichroism and absorption spectra of zinc phthalocyanine in an Ar matrix have been measured between ≈ 37000 and 74000 cm −1 with far better resolution than in previous absorption work on this or related systems. The spectral features beyond ≈ 45000 cm −1 can be roughly correlated with those of the isolated benzene molecule.