Increasing responsivity of THz radiation detector based on MOSFETs

Approaches based on thinning down the substrate under the antenna are often used in order to increase efficiency of detectors built with MOSFETs and antennae printed on thick substrates. Such detectors have relatively low responsivity. In applications where cheap individual pixels are required, standard silicon lenses used to increase the responsivity are prohibitively expensive. In this paper an alternative approach based on a CNC-milled parabolic mirror integrated in the package of the detecting chip is described and compared with results obtained with plastic lenses installed in front of the detector.