Nonlinear Optical Properties of Functionalized DNA-CTMA complexes

Nonlinear optical properties of functionalized deoxyribonucleic acid (DNA) are reviewed and discussed. The studies were performed on thin films of DNA-CTMA and DNA-CTMA complex doped with: a charge transfer molecules DR1, pi conjugated with 2D (cobalt phthalocyanine) and 3D delocalization (C-60 derivative PCBM). The NLO properties of these compounds were studied by optical third harmonic generation at 1064.2 nm fundamental wavelength and by degenerate four wave mixing techniques at 532 nm by nanosecond and picosecond pulsed lasers, respectively. Fast THG chi((3))(- 3(w;w,w,w) as well as the real and imaginary parts of Kerr chi((3))(-w;w-w,w) susceptibilities were determined. The studies show that DNA, similarly as synthetic polymers, can be used as matrix for highly active NLO chromophores. A peculiar behaviour is observed at low dopant level which is interpreted as due to the two photon resonance and its position dependence on the doping mechanism.