Modifying optical nonlinearities of ionic liquid crystal glass by adding gold and carbon nanoparticles

Abstract

Future disruptive photonics technologies depend on the development of new types of nonlinear-optical glass composites containing nanoparticles. In this paper, we report the synthesis, structural characterization, spectral and nonlinear-optical properties of overlooked yet very promising glass nanocomposites made of glass forming ionic liquid crystals (cadmium caprylate) and two types of nanoparticles (gold and carbon). Nonlinear-optical properties of the prepared nanocomposites are studied by means of a standard Z-scan method and using visible (532 nm) nanosecond laser pulses. By exciting glass nanocomposites within their absorption band, an interplay between several nonlinear-optical mechanisms can be revealed. A simultaneous use of two types of nanoparticles (i.e. carbon and gold) enables a better control over effective optical nonlinearities of nanocomposites. More specifically, by changing an intensity of a laser beam, it is possible to vary the magnitude of the effective nonlinear refractive index and of the effective nonlinear absorption coefficient. In addition, even the sign of the effective nonlinear absorption coefficient can be changed. The proposed strategy to create novel nonlinear-optical materials using metal-alkanoates based glass-forming ionic liquid crystals and several types of nanoparticles will benefit rapidly growing nanophotonics and plasmonics technologies.