Abstract

Nonlinear absorption in the Pt:Ethynyl complex [Bis((4-(phenylethynyl)phenyl)ethynyl) bis(tributylphosphine) Platinum (II)] has been investigated previously at wavelengths of 532 nm and 513 nm.^1-3 At these wavelengths it was shown that the nonlinear absorption is primarily a consequence of a direct transition from the S₀ ground state to the long-lived (0.3µs) excited T₁ state, followed by excited state absorption from T₁ to T^* (Fig. 1), resulting in efficient optical limiting over a range of pulse lengths from picoseconds to hundreds of nanoseconds.

© 1998 Optical Society of America