A High Temperature Superconductor (HTSC) Hot Electron (HE) THz Heterodyne Thermal Sensor (HTS): Computational Analysis of Conversion Gain in

The solution of the two temperature (electron and phonon) heat transfer equations, for nonequilibrium elctron–phonon cooling processes happening between electrons, sensor lattice, and the substrate system, is used to express the conversion gain of the thermal sensor in the form of a mathematical analytic expression. The full expression exposes the relative importance of various material and geometry dependent parameters of the device. The detector is pumped by a local infrared laser of picosecond pulses. The external signal is fed to the device through a chopper of frequency close to THz. It is found that in the band of operation GHz–THz frequency (), the time of escape of phonons (t_mes) to the substrate basically controls the performance of the sensor.