Transient nonlinear optical behavior of fluorescein-doped boric acid glass

Abstract

The nonlinear optical properties of fluorescein-doped boric acid glass films have been investigated with subnanosecond laser pulses. With the use of degenerate four-wave mixing, large third-order susceptibilities of X(3 10-' esu have been measured, connected to the relatively fast decay of the singlet state Si ( = 2.4 + 0.6 ns). This particular system has a long-lived lowest-lying triplet state (0.1-1 s), and the transient nonlinear-optical and fluorescence properties show a marked dependence on the laser-pulse repetition rate in this time regime.