Design of the Sub-wavelength Gratings Applying to Optical Current Transducers

Abstract In the optical current transformer the sub-wavelength metallic gratings are hopeful to substitute the traditional polarizer because of their excellent optical properties. In this paper, a powerful analysis and design tool used for the sub-wavelength grating is proposed based on Matlab and LabVIEW virtual instrument software architecture. The RCWA (coupled-wave analysis) accompany with the enhanced transmittance matrix approach and the method of Fourier factorization is applied for the analysis of the grating. In the software platform, the users can visually and simply design a grating with arbitrary groove profile or intelligently extract the groove profile from the grating actually produced by image processing. The values of the diffraction efficiency and grating extinction ratio depend on the various parameters of the grating and incident light can be analyzed through the results in the form of charts and tables.