We report the observation of a broadband continuum spanning from 350 to 470 nm in the black-light region of the electromagnetic spectrum as a result of picosecond pumping a solid-core silica photonic crystal fiber at 355 nm. This was achieved despite strong absorption and a large normal dispersion of silica glass in the UV. Further investigations reveal that the continuum generation results from the interplay of intermodally phase-matched four-wave mixing and cascaded Raman scattering. We also discuss the main limitations in terms of bandwidth and power due to temporal walk-off, fiber absorption, and the photo darkening effect, and we suggest simple solutions.
© 2012 Optical Society of America
Original Manuscript: September 15, 2011
Revised Manuscript: November 17, 2011
Manuscript Accepted: November 17, 2011
Published: January 9, 2012
T. Sylvestre, A. R. Ragueh, M. W. Lee, B. Stiller, G. Fanjoux, B. Barviau, A. Mussot, and A. Kudlinski, "Black-light continuum generation in a silica-core photonic crystal fiber," Opt. Lett. 37, 130-132 (2012)
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