Fabrication of Phase Reflection Sawtooth Gratings Optimized by Scalar and Vector Way by Using Diamond Cutting

Abstract

This paper presents optimization of phase reflection sawtooth gratings with a period of 2.0 μm and a depth of 0.2 μm based on the Fourier transformation (FT) and the rigorous coupled wave analysis (RCWA). And its fabrication on oxygen free Cu and electroless Ni-coated surfaces by using diamond cutting in a shaping process whose toolpath is interfered to provide smaller period. The diffraction efficiencies were estimated 100% for FT, 83.0% and 79.0% for TE and TM polarization of the incident light at a depth of 0.2 μm. It was found that electroless Ni-coated surface had better performance in terms of machining and optical functionality. From optical testing, the diffraction efficiencies were measured 84.0% and 84.4% for TE and TM polarization, respectively.