A formulation of rigorous coupled-wave theory for diffraction gratings in bianisotropic media that exhibit linear birefringence and/or optical activity is presented. The symmetric constitutive relations for bianisotropic materials are adopted. All of the incident, exiting, and grating materials can be isotropic, uniaxial, or biaxial, with or without optical activity. The principal values of the electric permittivity tensor, the magnetic permeability tensor, and the gyrotropic tensor of the media can take arbitrary values, and the principal axes may be arbitrarily and independently oriented. Procedures for Fourier expansion of Maxwell's equations are described. Distinctive polarization coupling effects due to optical activity are observed in sample calculations.

Recent improvements of plastics optics performance and manufacturing technology of plastics lenses have resulted in rapid application ofplastics optical elements. One of the thctors in delaying the applications ofthe plastics optical elements is the existence ofbirefringence in plastics lenses. It gives us a challenge to resolve the problem so that the plastics optical elements can achieve much higher levels of performance.It is generally recognized that the mechanism of birefringence generation is relevant to the resin behaviors during the injection molding process. If this mechanism is filly understood by flow analysis, it may be a great contribution to the fabrication ofplastics optical elements. However, conventional two-dimensional flow analysis on injection molding fails to grasp the phenomena ofbirefringence. In this paper, we have successfully identified some phenomena on injection molding that are closely related to the generation of birefringaice. We analyzed the phenomena in details in filling, packing, and cooling processes during the injection molding process using three-dimensional CAE system, called 3D TIMON. The analyzed results were confirmed experimentally and they enabled us to predict the generation of birefringence by CAE analysis.

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