▎ 摘　　要

The laser-driven white emission of graphene foam in a vacuum bulb was investigated. Thanks to high brightness of light emission attributed to multiphoton ionization, it was possible to construct a compact, spatially coherent, white light source. A new graphene foam bulb was designed to efficiently couple white light into a multimode fiber. The efficiency of coupling light to multimode fibers with varying core diameters was measured. It is concluded that the performance of the graphene foam bulb is close to that simulated for an ideal geometrical point source.