*3.3. Thermal Time Constant*

The thermal time constant represented the duration for the temperature change and output signals rising from 0 to 63.2% of the steady-state values, deriving from the responsivity versus modulation frequency [36]. The thermal time constant values of the proposed detector operating at 2.58 THz and 4.2 THz were extracted as 298 ms and 330 ms, respectively.
