Exploring Optical Nonlinearities of Glass Nanocomposites Made of Bimetallic Nanoparticles and Mesogenic Metal Alkanoates

The unique properties of nanomaterials along with their suitability for photonics applications can be explored by dispersing nanodopants in a transparent glass matrix. As a rule, the creation of glass nanocomposites involves a synthesis of nanoparticles followed by their dispersion in a glass host. This laborious two-step process can be simplified if glass-forming liquid crystals are used as a nanoreactor and host matrix. In this paper, we discuss a successful realization of this approach using mesogenic metal alkanoates for the fabrication of unconventional glass nanocomposites containing metal and/or bimetallic nanoparticles. More specifically, metal (gold and silver) and bimetallic (silver-gold) nanoparticles are synthesized in the liquid crystal phase of a glass-forming cadmium octanoate. Upon cooling cadmium octanoate samples containing the synthesized nanoparticles easily vitrify resulting in the formation of glass nanocomposites. The produced glass nanocomposites exhibit a relatively strong (10^-8 – 10^-7 esu) nonlinear-optical response tested by means of a Z-scan technique and utilizing visible (532 nm) and near-infrared (1064 nm) nanosecond laser pulses. The evaluated values of the effective nonlinear absorption coefficients and nonlinear refractive indices of the studied samples depend on their composition and on the intensity of laser beams thus revealing the presence of several nonlinear-optical mechanisms acting simultaneously. Potential applications of the designed glass nanocomposites are also discussed.