TeraFET detector for measuring power fluctuations of 4.75-THz QCL-generated radiation

We present the field-effect-transistor-based THz (TeraFET) detector as a tool for monitoring power and its low-frequency fluctuations of 4.75-THz quantum cascade laser (QCL). The resonant patch antenna coupled TeraFET was implemented in 90 nm CMOS technology. At 4.75 THz, detector exhibits area-normalized minimal noise-equivalent power (NEP) of 370 pW/√Hz and the maximum responsivity of 82 V/W.