Fig. 4

Effect of tapering of G0 or G2, as indicated, on the visibility, sensitivity, and transmission. The grating is modeled as a trapezoidal shape where the top duty cycle is smaller than or equal to the bottom duty cycle. The other grating in each simulation is modeled as a rectangular X-LIGA grating with a height of 180 µm and a duty cycle of 50 %. The intensity is expressed relative to that from a pure silicon grating. The highest sensitivity is reached at a duty cycle of 40 % top and bottom, marked by the red x, for both scenarios.