摘要
On-chip integrated laser sources of structured light carrying fractional orbital angular momentum(FOAM)are highly desirable for the forefront development of optical communication and quantum information-processing technologies.While integrated vortex beam generators have been previously demonstrated in different optical settings,ultrafast control and sweep of FOAM light with low-power control,suitable for high-speed optical communication and computing,remains challenging.Here we demonstrate fast control of the FOAM from a vortex semiconductor microlaser based on fast transient mixing of integer laser vorticities induced by a control pulse.A continuous FOAM sweep between charge 0 and charge+2 is demonstrated in a 100 ps time window,with the ultimate speed limit being established by the carrier recombination time in the gain medium.Our results provide a new route to generating vortex microlasers carrying FOAM that are switchable at GHz frequencies by an ultrafast control pulse.
基金
the support from the National Science Foundation(NSF)(ECCS-1932803,OMA-1936276,ECCS-1842612,DMR-1809518,and CNS-2011411)
U.S.Army Research Office(ARO)(W911NF-19-1-0249 and W911NF-18-1-0348)
Office of Naval Research MURI(N00014-20-1-2558)
partially supported by the NSF through the University of Pennsylvania Materials Research Science and Engineering Center(MRSEC)(DMR-1720530)
supported by the NSF National Nanotechnology Coordinated Infrastructure Program under grant NNCI-1542153.
