A Novel Optical Delay Line Using a Rotating Planar Reflector for Fast Measurement of a Terahertz Pulse

We propose an optical delay line using a rotating planar reflector (ODL-RPR) for the measurement of a terahertz (THz) pulse, where the optical delay length is determined as a function of the rotating angle of the reflector. The characteristics of the temporal waveform and the spectrum of THz pulses measured by using the ODL-RPR, even with a rather simple and robust structure, were shown to be comparable to the results obtained by using a conventional motorized delay line (MDL). These results imply that the ODL-RPR with a high-speed rotator is preferable for fast measurement of a terahertz pulse.