  We investigate the response of the micromechanical field-effect transistors
(MMFETs) to the impinging terahertz (THz) signals. The MMFET uses the
microcantilevers MC as a mechanically floating gate and the movable mirror of
the Michelson optical interferometer. The MC mechanical oscillations are
transformed into optical signals and the MMFET operates as the detector of THz
radiation with the optical output. The combination of the mechanical and
plasmonic resonances in the MMFET with the optical amplification enables an
effective THz detection.
