Control of the Birefringence Dispersion of an Optical Polymer by Doping with an Inorganic Crystal

The birefringence dispersion of a polymer film was controlled by doping with an inorganic birefringent crystal. Nanosized crystals of strontium carbonate (SrCO3) with a needlelike shape of average length of 192 nm were oriented during the preparation of the film by solvent casting, and the contributions of the SrCO3 crystals to the birefringence and to the birefringence dispersion of the composite film were analyzed. A SrCO3-doped polymer film with reverse birefringence dispersion was fabricated, and the birefringence dispersion of this film was shown to be successfully controlled by the presence of the crystals.