Super-Bloch oscillations(SBOs)are amplified versions of direct current(dc)-driving Bloch oscillations realized under the detuned dc-and alternating current(ac)-driving electric fields.A unique feature of SBOs is the c...Super-Bloch oscillations(SBOs)are amplified versions of direct current(dc)-driving Bloch oscillations realized under the detuned dc-and alternating current(ac)-driving electric fields.A unique feature of SBOs is the coherent oscillation inhibition via the ac-driving renormalization effect,which is dubbed as the collapse of SBOs.However,previous experimental studies on SBOs have only been limited to the weak ac-driving regime,and the collapse of SBOs has not been observed.Here,by harnessing a synthetic temporal lattice in fiber-loop systems,we push the ac-field into a strong-driving regime and observe the collapse of SBOs,which manifests as the oscillation-trajectory localization at specific ac-driving amplitudes and oscillation-direction flip by crossing collapse points.By adopting arbitrary-wave ac-driving fields,we also realize generalized SBOs with engineered collapse conditions.Finally,we exploit the oscillation-direction flip features to design tunable temporal beam routers and splitters.We initiate and demonstrate the collapse of SBOs,which may feature applications in coherent wave localization control for optical communications and signal processing.展开更多
基金supported by the National Natural Science Foundation of China(Grant Nos.12374305,12204185,11974124,62305122,62375097,and 12021004)the Natural Science Foundation of Hubei Province(Grant Nos.2022CFB036 and 2023AFB822)the Hubei Key Laboratory of Optical Information and Pattern Recognition,Wuhan Institute of Technology(Grant No.202202)
文摘Super-Bloch oscillations(SBOs)are amplified versions of direct current(dc)-driving Bloch oscillations realized under the detuned dc-and alternating current(ac)-driving electric fields.A unique feature of SBOs is the coherent oscillation inhibition via the ac-driving renormalization effect,which is dubbed as the collapse of SBOs.However,previous experimental studies on SBOs have only been limited to the weak ac-driving regime,and the collapse of SBOs has not been observed.Here,by harnessing a synthetic temporal lattice in fiber-loop systems,we push the ac-field into a strong-driving regime and observe the collapse of SBOs,which manifests as the oscillation-trajectory localization at specific ac-driving amplitudes and oscillation-direction flip by crossing collapse points.By adopting arbitrary-wave ac-driving fields,we also realize generalized SBOs with engineered collapse conditions.Finally,we exploit the oscillation-direction flip features to design tunable temporal beam routers and splitters.We initiate and demonstrate the collapse of SBOs,which may feature applications in coherent wave localization control for optical communications and signal processing.
