  In quantum optics, orbital angular momentum (OAM) is very promising to
achieve high-dimensional quantum states due to the nature of infinite and
discrete eigenvalue, which is quantized by the topological charge of l. Here, a
heralded single-photon source with switchable OAM modes is proposed and
demonstrated on silicon chip. At room-temperature, the heralded single photons
with 11 OAM modes (l=2~6, -6~-1) have been successfully generated and switched
through thermo-optical effect. We believe that such an integrated quantum
source with multiple OAM modes and operating at room-temperature would provide
a practical platform for high-dimensional quantum information processing.
Moreover, our proposed architecture can also be extended to other material
systems to further improve the performance of OAM quantum source.
