  For the first time, we demonstrated that a hyper-broadband from 2{\mu}m to
10{\mu}m can be generated with a high spectral flatness by using a ~4 um pump
and an As2Se3 photonic crystal fiber. The broad and flat dispersion profile and
the low guiding loss of the endlessly single-mode As2Se3 photonic crystal
fibers combining with the high nonlinearity and wide mid-infrared transparent
window of As2Se3 chalcogenide glass are essential for this high performance
mid-infrared laser source.
