A Study of the Nonlinear Optical Transmittance in a Variety of TCNQ-Based Organometallic Colloidal Suspensions

Abstract

Optical limiting in a series of novel aqueous colloidal suspensions is investigated. The suspensions consist of an organometallic charge-transfer complex based on the organic acceptor 7,7,8,8-tetracyanoquinodimethane (TCNQ). We report on the synthesis of the organometallic complexes and their effectiveness at limiting nanosecond pulses at 532 nm. It is shown that some of the charge-transfer systems can effectively attenuate pulses at rates up to 10 Hz while other systems require continuous agitation in order to most efficiently limit the laser radiation. Finally we discuss the reversible field-induced phase transition that produces the observed nonlinear absorption.