Optical nonlinearity of a sigma-pi photoconductive copolymer, poly(disilany
lene-2, 2 ' -bipyridine-5, 5 ' -diyl) ruthenium complex, has been investiga
ted in chloroform solution of various concentrations. The nonlinear optical
absorption resulted in optical limiting, optical bistability, and laser pu
lse compression for nanosecond pulses at the wavelength of 532 nm. Theoreti
cal analyses showed that the optical absorptive nonlinearity was dependent
on the photogenerated excitons and exciton-exciton couplings. (C) 2000 Else
vier Science B.V. All rights reserved.