Fig. 9: Grating design and fabrication process.
a Schematic of the hexagonal grating chip showing a side-to-side length of 17.5 mm and three grating areas symmetrically arranged in the circular shape. The non-grating flat edges are used for the grating retainer clips. The 1/e2 beam diameter of the cooling beam is 28 mm truncated to ≈19 mm by the fused silica viewport. b Fabrication process of the GMOT grating chip. Parameters for the grating chip used in this paper are tAl = 50nm, \({{{{{{\rm{t}}}}}}}_{{{{{{{\rm{SiO}}}}}}}_{2}}\) = 195 nm, d = 1.2 μm, and ~ 50% duty cycle (details in main text).
