Photonics and Nonlinear Optics with Sol-Gel Processed Inorganic Glass:Organic Polymer Composites

Abstract

Nonlinear optics is at the forefront of current research because of its vital role in optical processing of information. A composite structure offers the opportunity to optimize each necessary property independently to produce useful materials for photonics. This review discusses the merits of novel glass phase composites for photonics, specifically a new class of inorganic oxide glass: organic polymer composites prepared by sol-gel processing. Stable electric field induced alignment has been achieved for second-order nonlinear optical effects such as second harmonic generation and electro-optic modulation. In-situ study of the relaxation behavior of the nonlinear optical response in electrically aligned sol-gel composites also provides an opportunity to study their microstructure. Recent success in making high concentration, up to 50% by weight, and optically transparent composites of inorganic oxides and conjugated polymers has opened up a promising avenue to make third-order nonlinear optical materials for integrated optics. In the inorganic glass:conjugated polymer composites, prepared for third-order nonlinear optical effects, the nonlinear optical response has been investigated using femtosecond degenerate four wave mixing, Kerr gates and transient absorption. Saturable absorption processes in a laser cavity have been studied for Q-switching and mode-locking applications.