SBIR-STTR Award

There is a need for lightweight high-density (4000+ lines/mm) novel diffraction grating elements in modern telescopes to advance EUV and X-ray astrophysics. Current grating technologies (ruling and holographic beam interference) do not provide optimal solution for all grating requirements. In response to NASA request, we propose to apply state-of-the art DUV reduction photolithographic tools developed for modern semiconductor industry and LightSmyth's proven design expertise in the application of this technology to the development of grating devices with constant and varying line spacing (VLS). The proposal will focus on four major areas: (i) Development and demonstration of constant and VLS reflective diffraction grating elements for EUV and X-ray spectroscopy at glazing angle of incidence with straight lines. (ii) Development and demonstration of VLS reflective diffraction grating elements for EUV and X-ray spectroscopy at glazing angle of incidence with curved lines to produce focusing diffraction grating elements on a plane substrate. (iii) Design of in-plane and off-plane reflective diffraction grating elements for NASA's Constellation-X. (iv) Design of VLS blazed near-normal incidence focusing diffraction grating elements on plane substrate for EUV imaging spectroscopy to replace diffraction grating on toroidal substrate for Goddard Space Flight Center's NEXUS project.

Diffraction gratings are powerful tools for the spectral analysis of electromagnetic radiation. Properties of gratings are determined by available fabrication means ? which have not changed substantially in 50 years. Modern photolithography, now approaching nanometer resolution, may revolutionize the way many gratings are made and, through greater design flexibility, how gratings function. Over 1011 pixels, each smaller than 100 nm and collectively spanning areas of multiple centimeters, can be addressed individually with nanometer-scale absolute positioning accuracy by modern lithographic tools, thereby making it possible to create gratings with virtually any desired line curvature, variable line spacing, length and thickness ? features largely beyond traditional fabrication means. LightSmyth Technologies proposes to leverage these state-of-the-art photolithographic patterning tools to design flat imaging gratings that combine dispersive grating function with one- and two-dimensional focusing. Importantly, diffractive, aka holographic, focusing may have substantially lower aberration in low f-number or high incidence angle configurations. Line spacing and curvature do the focusing. This design and fabrication strategy will be applied to the development of gratings for NASA's NEXUS effort and other advanced grating products of value to NASA and the commercial markets ? all of which leverage on the innovative fabrication platform LightSmyth brings to the diffractive market.