Dynamic population difference gratings and microcavities induced by extremely short pulses: recent advances and future prospects (brief review)

This review highlights recent advances in the creation of atomic population gratings using multi-cycle and extremely short light pulses in a medium. The application of these structures in transient grating spectroscopy is discussed. Special attention is given to the formation of high-quality dynamic microcavities, a novel type of structure recently predicted by the authors, which arises from collisions of extremely short half-cycle pulses within a medium. The results demonstrate the potential for attosecond optical switching of matter states at petahertz frequencies, operating within extreme time scales of half a field oscillation cycle. These findings pave the way for groundbreaking applications in modern ultrafast optics, including petahertz-scale signal processing, attosecond coherent control, and the development of next-generation optical technologies operating at the fundamental limits of speed and precision.