Population difference gratings induced in a resonant medium by a pair of short terahertz nonoverlapping pulses

We show that, using a pair of short terahertz pulses, it is possible to form light-induced gratings of the population difference, which can be applied to control terahertz radiation. The pulses coherently interact with the medium and do not overlap in it. The examined effect opens up new opportunities in terahertz spectroscopy with the use of such short pulses.