摘要
Time-varying media have recently emerged as a new paradigm for wave manipulation,due to the synergy between the discovery of highly nonlinear materials,such as epsilon-near-zero materials,and the quest for wave applications,such as magnet-free nonreciprocity,multimode light shaping,and ultrafast switching.In this review,we provide a comprehensive discussion of the recent progress achieved with photonic metamaterials whose properties stem from their modulation in time.We review the basic concepts underpinning temporal switching and its relation with spatial scattering and deploy the resulting insight to review photonic time-crystals and their emergent research avenues,such as topological and non-Hermitian physics.We then extend our discussion to account for spatiotemporal modulation and its applications to nonreciprocity,synthetic motion,giant anisotropy,amplification,and many other effects.Finally,we conclude with a review of the most attractive experimental avenues recently demonstrated and provide a few perspectives on emerging trends for future implementations of time-modulation in photonics.
基金
funding from the Engineering and Physical Sciences Research Council via an EPSRC Doctoral Prize Fellowship (Grant No. EP/T51780X/1)
a Junior Fellowship of the Simons Society of Fellows (855344,EG)
funding from Fundação para a Ciência e a Tecnologia and Instituto de Telecomunicações under project UIDB/50008/2020
funded by the CEEC Individual program from Fundação para a Ciência e a Tecnologia with reference CEECIND/02947/2020
funding from the Engineering and Physical Sciences Research Council (EP/V048880)
funding from the Gordon and Betty More Foundation
funding from the Department of Defense, the Simons Foundation
the Air Force Office of Scientific Research MURI program
