Triplet state characteristics of IR laser dyes: A pulse radiolysis study

Abstract

The IR-dyes, having the absorption maximum in the range of 600 nm to 1100 nm, are expected to have very low triplet energy level. The triplet-triplet <i>(T-T) </i>absorption spectra and decay characteristics have been investigated for four IR laser dyes, namely, IR-140, IR-144, Q-Switch I and Q-Switch 5. Triplet state of these IR dyes are generated by electron pulse radiolysis in benzene-benzonitrile (BZ-BZN 80:20, % <i>v/v) </i>solvent mixture. Energy transfer from the pulse radiolytically generated anthracene triplet confirms the formation of triplet state of these IR dyes. Triplet state characterist ics of these IR dyes have been measured. Using various triplet donors and acceptors, the triplet energy levels of these dyes have been estimated.