Parallel generation and coding of a terahertz pulse train

Abstract

Packet-modulated communication may play a pivotal role in the future of short-range communications at terahertz (THz) frequencies. As with ultra-wideband communication, the advantageous of this type of communication are its extremely short duration, immunity to multipath fading, wide bandwidth and low power spectral density. However, due to the lack of a fast modulation method, packet-modulated pulse communication at THz frequencies has not yet been demonstrated. Here we present a method for the generation and modulation of a coded THz pulse train. Our scheme is based on the combination of a spintronic THz emitter (STE) with an echelon mirror and a digital micromirror device. This highly scalable configuration is capable of modulating hundred or more THz pulses in parallel with sub-picosecond accuracy and is versatile for various modulation protocols. Strikingly, the temporal resolution of our modulation scheme depends on geometric optics and not on a high-speed electronic device. Furthermore, the ability of STEs to generate quasi-continuous THz pulses offers an alternative solution to the photomixer, a key THz communication technology, and thus could lead to a promising new THz communication modality.