Abstract

Saturable absorption (SA) in organometallic compounds, such as phthalocyanine (Pc), was extensively studied in 1960’s, the purpose of the research was to find suitable dyes to compress laser pulse. As we know, SA is due to the absorption of the ground state, which can be described by a two-level model or a three-level model^[1]. At that time, the excited state absorption, only considered as residual absorption, had not received much attention.

© 1992 Optical Society of America