Terahertz polaritonics: spatiotemporal imaging, spatiotemporal femtosecond pulse shaping, and spatiotemporal coherent control

Spatiotemporal pulse shaping is used to transform a single femtosecond excitation pulse into a spatially and temporally tailored output which may take the form of many separate beams, each of which has an independently specified time-dependent waveform. Through impulsive stimulated Raman scattering, the separate beams and pulses excite coherent phonon-polaritons and manipulate them as they propagate within the crystalline sample at light-like speeds. Variably delayed probe pulses are expanded to a large size within the sample and projected onto a CCD camera to record real-space images of the propagating responses. The images are used to guide the spatiotemporal pulse shaping and coherent control processes