High-power terahertz pulse sensor with overmoded structure

Based on the hot electron effect in a semiconductor, an overmoded resistive sensor for 0.3-0.4 THz band is investigated. The distribution of electromagnetic field components, voltage standing wave ratio (VSWR), and the average electric field in the silicon block are obtained by using the three-dimensional finite-difference time-domain (FDTD) method. By adjusting several factors (such as the length, width, height and specific resistance of the silicon block) a novel sensor with optimal structural parameters that can be used as a power measurement device for high power terahertz pulse directly is proposed. The results show that the sensor has a relative sensitivity of about 0.24 kW^-1, with a fluctuation of relative sensitivity of no more than ± 22%, and the maximum of VSWR is 2.74 for 0.3-0.4 THz band.