In-Fiber Magneto-Optic Devices Based on Ultrahigh Verdet Constant Organic Materials and Holey Fibers

摘要

A high sensitivity Verdet constant measurement system was developed that obtained Verdet constants for commercially available standards in excellent agreement with the literature. We have observed Verdet constants of approximately 100,000 degrees/T-m in regioregular polythiophenes and shown that the regioregularity and processing conditions critically effect their properties. New magnetite nanoparticle/acrylate polymer core/shell nanocomposites with exceptional transparency across the visible/IR have been developed. These composites exhibit Verdet constants > 100,000 degrees/T-m in pristine films and > 1,000,000 degrees/T-m in magnetic field poled films at a few weight percent nanoparticle loading. Our unique polymer synthesis allows us to tune the refractive index of the final composite. We have demonstrated waveguide Faraday rotation (2 degrees) using a magnetic field poled nanocomposite as the cladding for a sol-gel waveguide core, and further optimization of optical properties, poling, magnetic field delivery and nanoparticle loading should give the rotation required for an isolator. A garnet-based magnetic field sensor working at about 100 pT has also been demonstrated. KU Leuven provided regioregular polythiophenes and magnetite nanoparticles for our studies.