High Resolution Lensless THz Imaging with an Ultrafast TDS System

In this paper, we employ an ultrafast THz time-domain spectroscopy (TDS) system for computationally efficient imaging using a Kirchhoff migration algorithm. The imaging method makes use of uncollimated, unfocused terahertz beams, and eliminates the need for any opto-mechanical elements. Moreover, this method compensates for the low signal-to-noise ratio obtained with an uncollimated THz beam. We use a THz TDS system based on electronically controlled optical sampling (ECOPS), which achieves a measurement rate of 1600 traces per second. We validate the performance of the method with three different objects.