<title>Investigation of relaxation times of polymethine dyes absorbing in 750-850 nm spectral range</title>

Abstract

The relaxation times ((tau) ) of the first excited state of cationic symmetric polymethine dyes absorbing in the spectral range of 750 - 850 nm have been determined by a direct pump and probe method. The influence of the dye structure and solvent nature on the value of (tau) is discussed. The role of different intra- and intermolecular interactions in deactivation of the excited state of the dyes is considered. The perspective polymethine dyes ((tau) equals 11 - 75 ps) for passive mode locking of lasers on LiGaAlF6:Cr3+, KZnF3:Cr3+, and LiSrAlF6:Cr3+ crystals are proposed from the analysis of relaxation times.© (2002) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.