Enhancement of two-photon absorption in tetrapyrrolic compounds

• DOI: 10.1364/josab.20.000321
• Publication Date: 2007-08-17T17:03:16Z
• Authors: Aliaksandr Karotki; Mikhail Drobizhev; Mikalai Kruk; Charles Spangler; Erik Nickel; Nugzar Mamardashvili; Aleksander Rebane
• Keywords: Absorption cross section; Two-Photon Absorption

We study the enhancement of two-photon absorption (TPA) in a series porphyrins and tetraazaporphyrins by measuring absolute TPA cross sections with 100-fs-duration pulses two ranges laser wavelengths, from 1100 to 1500 700 800 nm. The section Q transition region is σ2∼1–10 GM (where 1 GM=10-50 cm4 s-1 photons-1), value that explained partial lifting prohibition due parity selection rule. In Soret we find σ2 ∼1 order magnitude owing transition, which acts as near-resonance intermediate state, also presence gerade energy levels, identify this spectral region. symmetrically substituted strong electron acceptors, further (up σ2∼1600 GM). As possible application, demonstrate for first time our knowledge photosensitization singlet-oxygen luminescence porphyrin.