Ultrafast control of fractional orbital angular momentum of microlaser emissions

摘要

An InGaAsP microlaser is embedded in a Si3N4 substrate and coupled with an external control arm, both pumped by ultrafast pulses, enabling the desired spin–orbit interactions. By controlling the time delay between the control and pump pulses, the FOAM of laser emissions can be temporally modulated with a picosecond resolution. The inset indicates the spatially varying electric field distribution showing the vectorial nature of the FOAM emission (see Supplementary Information for experimental measurements), assuming contributions from all four spin–OAM components in Eq. (4)