Fabrication of high-efficiency convex blazed gratings by swing ion beam etching

We use the swing ion-beam etching method to fabricate short wave infrared convex blazed gratings. This method solves the consistency problem of blaze angles by swing etching through the meridian direction of the gratings. A geometric model is built to analyze the influence of swinging speed and beam slit width on groove evolution. Convex gratings with a 45.5 gr/mm groove density, 67 mm aperture, 156.88 mm radius of curvature and 2.2 ∼ blaze angle have been fabricated and measured. Experimental results validate that high-efficiency convex gratings of small blaze angle and high groove consistency can be produced by swing etching to satisfy the requirements for high spectral resolution and miniaturization of imaging spectrometers. (authors)