Diamond machining of diffraction gratings for imaging spectrometers

High quality imaging spectroscopy data is useful for both military and civilian applications. State-of-the art spectrometers incorporate spherically concentric, axially symmetric and telecentric optical design. However, these designs require a diffraction grating operating in reflection that is manufactured on a convex, spherical or possibly freeform surfaces, and thus traditional grating manufacturing methods limit modern designs and raise costs. Further, it is often desirable to manufacture such optics in a monolithic configuration aligning them and eliminating assembly. This paper explores the capability of new 5-axis ultra-precision machine tools for manufacturing diffraction gratings in simplified experiments aimed at progressing toward producing gratings on freeform surfaces and monolithic combined optical designs. (C) 2011 Elsevier Inc. All rights reserved.