Structures with one and two courses of apertures around a central lightguide core whose diameter varies from 1 to 4 mm have been implemented. The radiation losses were about 1 dB/ m. When the lightguide is excited with the radiation of a Ti-sapphire laser having a pulse width of 30 fs and an energy around 1 nJ, efficient lasing of continuous radiation is obtained in the spectral range from 400 to 900 nm.
K. V. Dukel'skii, Yu. N. Kondrat'ev, G. T. Petrovskii, A. V. Khokhlov, A. M. Zheltikov, A. A. Shamko, and V. B. Smirnov, "Implementation of a photonic crystal fiber lightguide and generation of broad-band laser radiation in it," J. Opt. Technol. 70, 612-614 (2003)