THz Pulse Holography

Abstract

The main idea of the suggested THz holographic system is to measure amplitude-phase diffraction patterns of an object at the spectrum range of 0.5..4 THz (8 octaves) and further digital processing of obtained data. The ultrabroadband THz electric field of diffraction patterns of an object at the distance can be recorded by electro-optic sampling. Using optical delay line we change THz and fs pulses superposition in electro-optic crystal and thus we can obtain THz field time dependence at each image point E (x, y, t). Using Fourier transform of E (x, y, t) we can obtain spectrum at every image point. Due to reversibility of Maxwell equations we can consider wavefront conjugation in time by changing monochromatic components into their complex conjugates. Thus, we can obtain original electric field in object plane for each wavelength component. As we can obtain complete (holos) information of the object by this approach, it can be named a THz pulse holography. To check this method verifying numerical calculations have been carried out and the holograms of amplitude and phase arbitrary shaped transparencies were obtained and reconstructed numerically.