Absolute Amplitude Measurement of Terahertz Pulse Waveform on Wafer

A method of absolute amplitude measurement of terahertz pulse waveform on wafer based on electro-optic sampling (EOS) is introduced in this paper. The method starts by calibrating the EOS system using square waveforms with known amplitudes as reference signals to obtain the linear relationship coefficients of the experimental setup. After that, the calibrated experimental setup is used to measure the terahertz pulse waveform with amplitudes ranging from 50m V to 500m V outputted by a broadband photodetector (PD), and the results are compared with those measured by a 70GHz sampling oscilloscope. The good consistency verifies that the calibrated system can realize the measurement of absolute amplitude of terahertz pulse waveform on wafer.