Figure 9.
Map of room temperature emitting and sensing devices in a logarithmic THz frequency scale. The considered devices are plotted with respect to the emitting power in sources section (left) and the noise equivalent power in sensors one (right). Taken data references: Schottky diodes multipliers [87,439] CMOS-based and SiGe-based electronic emitters [62]; CMOS and SiGe detectors parameters [159], parameters of Schottky detectors [440], microbolometers values [167], conventional THz QCL [41]; frequency-difference THz QCLs (FD THz QCLs) parameters—from publications by M. Razeghi [51,52] and M. Belkin’s [53] groups. Optoelectronic THz systems (denoted as red solid lines) are attributed for the emitters section only. The left red solid line depicts facilities of optoelectronic InGaAsBi-based systems [36], the right one—the system relying on InGaAs:Rh compound [37]. Resonant tunneling diodes data are taken from publications by M. Asada [119,121], M. Feiginov [117] and H. Yokoyama [441] groups. Shaded ares denote schematically possible complementary components in a design of compact THz imaging systems in respect to the THz frequency scale. One can note that compact room temperature THz imaging systems can be constructed, for instance, using FD THz QCLs and silicon nanometric transistors or microbolometers. It is seen that RTD devices can be used together with Schottky diodes, silicon nanoFETs, microbolometers and bow-tie diodes [181]. One can mention that CMOS technology-based mixers and oscillators in imaging can be nicely fitted together with nanometric FETs and microbolometers, as well as Schottky or bow-tie diodes. Graphene-based room-temperature THz detector’s parameters are taken from publications of the H. G. Roskos [163], J. Stake [442], and M. S. Vitiello groups [164].