7-cell core hollow-core photonic crystal fibers with low loss in the spectral region around 2 μm

Several 7 cell core hollow-core photonic crystal fibers with bandgaps in the spectral range of 1.4 mu m to 2.3 mu m have been fabricated. The transmission loss follows the approximate to lambda(-3) dependency previously reported, with a minimum measured loss of 9.5 dB/km at 1.99 mu m. One fiber with a transmission loss of 26 dB/km at 2.3 mu m is reported, which is significantly lower than the transmission loss of solid silica fibers at this wavelength. (C) 2009 Optical Society of America