Keywords: Double random phase encoding, dual-mode, electro-optical sampling, heterodyne detection, holography, information security, optical encryption, nonlinear crystal, photomixers, photoconductive antenna, phase retrieval, quantum dot (QD), quantum cascade laser (QCL), resonant tunnelling diode (RTD), semiconductor lasers, THz imaging, THz radiationgeneration and detection, ultrashort pulse, uni-travelling-carrier photodiode (UTC-PD)