Fabricate Blazed Concave Gratings by Curing Ion Beam Etching

Abstract

Diffraction efficiency is an important performance indicators of the type IV concave grating, and parallel ion beam etching etching process is difficult to obtain a high diffraction efficiency of type IV concave grating. External controllable magnetic field leads to the parallel ion beam to achieve the deflection of the ion beam is a novel means for the realization of a type IV along the curved surface of the concave grating different blaze angle ion beam etching, and in this way possible to obtain a high diffraction efficiency type IV concave grating. After a theoretical design ideal type IV concave grating blaze angle, use of the holographic exposure - bending ion beam simulation etching size 45 × 40mm2, wavelength 250nm at diffraction efficiency of 67%, the arm is 200mm, 188mm, the radius of curvature 224mm of type IV concave grating. Meanwhile, the use of parallel ion beam current of the same parameters of the analog etching type IV concave grating, the diffraction efficiency at 250nm was 30%. The simulation results show that the bending ion beam produced type IV concave grating principle of the method is feasible, and the ability to precisely control the ion beam the concave grating type IV high diffraction efficiency production.