  Photons occupying multiple spatial modes hold a great promise for
implementing high-dimensional quantum communication. We use spontaneous
four-wave mixing to generate multimode photon pairs in a few mode fiber. We
show the photons are correlated in the fiber mode basis using an all-fiber mode
sorter. Our demonstration offers an essential building block for realizing
high-dimensional quantum protocols based on standard, commercially available
fibers, in an all-fiber configuration.
