Dramatic enhancement of intrinsic two-photon absorption in a conjugated porphyrin dimerElectronic supplementary information (ESI) available: Experimental procedures. See http://www.rsc.org/suppdata/cp/b3/b313399k/

Abstract

We report strong cooperative enhancement of simultaneous two-photon absorption cross section in a porphyrin dimer. The two-photon cross section, σ₂ = 6 × 10⁻⁴⁷ cm⁴s/photon, corresponds to a 400-fold increase over the value measured for the monomer, and is one of the largest ever obtained for organic chromophore of similar size.