  Quasi error-free 10 Gbit/s data transmission is demonstrated over a novel
type of 50 micron core diameter photonic crystal fiber with as much as 100 m
length. Combined with 850$ nm VCSEL sources, this fiber is an attractive
alternative to graded-index multi-mode fibers for datacom applications. A
comparison to numerical simulations suggests that the high bit-rate may be
partly explained by inter-modal diffusion.
