Hybrid Nonlinear Optical Materials for Applications in Power Limiting and Photorefractive Devices
Abstract
During the period covered by this project, our research efforts have been focused on the following subjects: (1) designing and synthesizing highly multi-photon active organic chromophores, (2) exploring novel organic/inorganic composite materials and enhanced mechanisms for optical limiting applications, and (3) utilizing nano-technology to improve the performance of organic photorefractive materials working in IR wavelength range. Since 2008, we have successfully synthesized two groups of chromophores that exhibit high two-photon absorbability: one is a group of laddertype oligo-p-phenylene cored chromophores useful for optical limiting; the other is a nitrosyl complex for light activated therapy through nitric oxide release. From the view-point of optical limiting applications, a solid two-photon absorbing material is much better than a solution or liquid medium, therefore we have developed a novel chromophore (AF289) doped polystyrene rod system, which manifests an excellent chemical/physical stability and provides a superior optical limiting and stabilization capability working with tilde 800-nm and tilde 160-fs laser pulses. In respect to photorefractive study, our other recent achievement is the optimization of photosensitivity in hybrid nano-composites containing lead sulfide (PbS) nanoparticles (NPs) with optical activity in near-infrared (NIR) spectral range. To improve the optoelectronic properties, we have applied a ligand de-protection strategy to demonstrate a relative improvement in the efficiency of a charge generation of hybrid PR composites for PR applications. The resulting shortened ligands on NCs lead to enhancement of both photocurrent and diffraction efficiency in corresponding film devices. As a result, the photon generation quantum efficiency in photoconductivity study was improved to be over 20%, and the two-beam coupling (TBC) gain coefficient was pronounced as 173 cm(-1).
Document Details
- Document Type
- Technical Report
- Publication Date
- Mar 01, 2010
- Accession Number
- ADA515413
Entities
People
- Paras Nath Prasad
Organizations
- University at Buffalo