A normal incident quantum cascade detector enhanced by surface plasmons

We demonstrate a normal incident quantum cascade detector excited by surface plasmons resonance using an Au two-dimensional hole array integrated on top of the detector absorption region. With normal incidence, the device has a maximal responsivity value of 8.4 mA/W at 160 K and can work up to room temperature with a responsivity of 1.02 mA/W. Compared with the 45° polished edge coupling device, the two-dimensional hole array can lead to quantum efficiency enhancement at most measured temperatures, and at 140 K the quantum efficiency is enhanced most strongly by 69%.