Corrélation entre possibilité d'effet laser et force oscillatrice de la transition fluorescente : cas des sels de pyrylium

Abstract

Laser action is demonstrated to occur in seven pyrylium salts between 4100 and 5100 Å with quantum yields extending from 4% to 12%. Theoretical calculations of the energy and oscillator strength of S0 → Sn transitions confirm band assignments deduced from experimental results. These results allow detection of a weak hidden transition in the 2,6-dimethyl-4-phenyl-pyrylium cation where laser action is not observed. This shows how important the magnitude of the oscillator strength of the first transition S0 → S1 is in selecting candidates to laser action. [Traduit par le journal]