Fig. 2: Details of the metal grating array.
From: Photon-trapping-enhanced avalanche photodiodes for mid-infrared applications
a, Designed dimensions. b, Scanning electron microscopy image of the fabricated photon-trapping SACM APD. The inset shows a high-magnification view of the grating region. c, Simulated EQE of the photon-trapping SACM APD with the designed grating dimensions; the dashed lines show the EQE of the first 2 µm AlInAsSb SACM APD with a 1-µm-thick absorber11. d, Normalized distribution of the square of the magnetic-field intensity |H|2 at the cross section of the device. The region between the two dashed lines represents the 200-nm-thick Al0.3InAsSb layer.
