Impact of Nanograting Phase-Shift on Light Absorption
Enhancement in Plasmonics-Based Metal-Semiconductor-Metal
Photodetectors
Figure 5
Total electric field intensity distribution in the cross-section of computational volume behind the nanograting with different grooves cross-section and the following grating parameters: the nanograting height is 90 nm, unperturbed gold (Au) layer thickness is 10 nm, grating period is 810 nm, and the sub-wavelength aperture width is 100 nm. The color scale has been optimized for representing small weak-field intensity variations. The nanograting profiles are (a) rectangular shaped (aspect ratio 1) with the grating phase shift 0°, (b) trapezoidal shaped (with an aspect ratio of 0.8) with a grating phase shift of ~45°, and (c) trapezoidal shaped (with an aspect ratio of 0.5) with a grating phase shift of ~90°.
