Roadmap on spatiotemporal light fields

Abstract

Spatiotemporal sculpturing of light pulse with ultimately sophisticated structures represents the holy grail of the human everlasting pursue of ultra-fast information transmission and processing as well as ultra-intense energy concentration and extraction. It also holds the key to unlock new extraordinary fundamental physical effects. Traditionally, spatiotemporal light pulses are always treated as spatiotemporally separable wave packet as solution of the Maxwell’s equations. In the past decade, however, more generalized forms of spatiotemporally nonseparable solution started to emerge with growing importance for their striking physical effects. This roadmap intends to highlight the recent advances in the creation and control of increasingly complex spatiotemporally sculptured pulses, from spatiotemporally separable to complex nonseparable states, with diverse geometric and topological structures, presenting a bird’s eye viewpoint on the zoology of spatiotemporal light fields and the outlook of future trends and open challenges.

Spatiotemporal mode-locking and dissipative solitons in multimode fiber lasers

“…Such applications would require customized 3D pulses. The customization is a nontrivial and challenging inverse problem for STML lasers complicated by spatial-mode-coupling, nonlinearity, and dissipation in MMF lasers 188 . On the other hand, engineered beam is not always needed and spatiotemopral coherence can be used as a knob to enable new applications 189 .…”

Ptychography for Multidimensional Characterization of Spatiotemporal Ultrafast Pulses

“…Over the years, ultrafast optics techniques have found a myriad of applications in nonlinear optics, microscopy, ultrafast lasers, , optical communications, and micromachining . Recently, many efforts have been devoted to developing novel techniques to synthesize ultrashort light pulses with on-demand spatiotemporal configurations . Experimental demonstrations of such spatiotemporal light states include the generation of propagation-invariant optical wave packets with controllable group velocity, , spatiotemporal orbital angular momentum (OAM) dynamic beams, − and toroidal photonic vortices. , A key requirement for utilizing spatiotemporal light structures in their entirety is the capability to accurately discern their physical properties.…”

Roadmap on structured waves

“…One can notice the rapidly growing interest in such directions as: temporal structures, including time-dependent media [17], space-time structured waves [18,19], and spatiotemporal vortices [20][21][22][23][24][25]; novel functionalities involving complex waves in non-Hermitian [26][27][28][29], topological [30,31] and random [32,33] media; 3D topological polarization structures including polarization Mobius strips [34][35][36][37][38], skyrmions [38][39][40][41][42][43][44][45][46] and structured polychromatic fields with commensurable frequencies [47][48][49][50][51]; spin and polarization properties of sound [52][53][54][55][56][57][58], elastic [59][60][61]…”