Effective multi-photon absorption properties in solutions of pyridinium salt lasing dyes

Three- and four-photon absorption induced processes of six new styrylpyridinium motif dyes are studied. Their largest 3-photon absorption cross-section is 29.9 times of Rhodamine 6G. Effective 3- and 4-photon absorption induced amplified spontaneous emissions are observed. The efficiency of 3-photon absorption induced lasing reaches 5.4%. Their large 3-photon absorption cross-sections mainly result from large conjugated plane and large dipole moment, and also relate to their counter ions. Their high efficiencies of 3-photon absorption induced lasing imply that 3-photon absorption process is possible to satisfy the conditions for practical applications. (c) 2007 Elsevier B.V. All rights reserved.