The Design And Fabrication Of Convex Blazed Grating

The fabrication and characteristics of convex blazed grating are investigated theoretically and experimentally in the paper. The main contents are as follows:The significance of the research of the convex blazed grating and the progress abroad and home of the research on convex blazed grating are presented. The meanings of ion-beam etching for the fabrication of phase mask are discussed, and the progress of the research on ion-beam etching are introduced.For efficiency calculation ,rigorous coupled-wave theory are introduced in detail. A computer code based on the diffraction theory was written ,which discusses the diffraction efficiency of rectangular and blazed plane grating. And research shows duty cycle,groove depth and blaze angle affect deeply the diffraction efficiency. At the same grating period ,the blazed grating have a higher diffraction efficiency than the rectangular grating. Meanwhile, the convex grating's efficiency was calculated.For etching characteristics of materials, The theory of ion-beam etching and ion sources are reviewed. The classification and main technical parameter of ion-beam etching are introduced. Etching characteristics of materials,including PR,K9,are investigated.The etch rate and mechanisms of materials are measured and analyzed as a function of ion energy,ion incidence angle in pure argon and fluoroform ,respectively.The etch rate has shown a square root dependence on variation versus.It offers useful experiment gist and theoretical instruction for the etching progress.For fabrication technique,a practical method to make high-quality blazed grating is developed.This method use an argon ion-beam to directly etch the K9 substract through a photoresist mask.The process of the small blaze angle plane grating making is introduced in detail. By reforming the etching machines,a small blaze angle convex grating was fabricated . It's evident that with this fabrication technique,blazed grating with sharp edges can be reproducibly fabricated ,and the control precision of the blaze angle is±10%.Finally,making aluminum on the convex(plane) grating samples,and designing a optical paths to measure the efficiency of the first order diffraction beams. In visible light, the plane grating has an average efficiency more than 60% , convex grating has 50% nearly.