O. Varnavski et al., Nonlinear optical properties of water-soluble polymeric dyes with biological applications, MACROMOLEC, 33(11), 2000, pp. 4061-4068
The nonlinear optical properties of two water-soluble polymeric dyes, poly(
R-478) (an anionic anthraquinone dye) and poly(S-119) (an anionic azo dye),
are investigated utilizing nanosecond and femtosecond optical techniques s
uch as z-scan, nonlinear transmission, and time-resolved luminescence. Poly
(R-478) showed large nonlinear refraction when studied with femtosecond las
er pulses at 800 nm, with a value for the intensity-dependent refractive in
dex (n(I)) of 1.26 x 10(-4) cm(2)/GW. The thin film result at 1064 nm indic
ated a large nonlinear absorption in both polymeric dyes. The origin of the
large fast optical nonlinearities in the polymeric system S-119 was invest
igated by probing the different functional groups of the polymer. The chrom
ophore group (Sunset Yellow) of the S-119 polymer showed a smaller nonlinea
r response when compared to the polymer result. Significant differences in
the electronic dynamics between the parent poly(S-119) and the chromophore
Sunset Yellow were observed by time-resolved luminescence spectroscopy. The
applications of the NLO effects in these polymers are demonstrated for las
er ablation of A549 lung carcinoma cells.