Supplementary data for "A chirped photonic-crystal fibre"
Photonic crystals have widely increased the facility to guide and confine light at wavelengths close to the optical wavelength1, 2, 3. Because they can include extremely sharp bends, photonic-crystal waveguides are a key element in future integrated optical devices4. Moreover, they enable the manipulation of the spontaneous emission properties of luminescent devices5, the localization of light in microcavities6, and they may serve to generate negative refraction7, 8. A special class of these devices are the hollow-core photonic-crystal fibres9, 10, 11, which confine the light by means of a periodic cladding, consisting of several layers of identical cells. This design resonantly decreases the transmission losses of such fibres to values of a few dB km-1 in a narrow wavelength range. However, the rather narrowband transmission bands and the detrimental third-order dispersion characteristics of this single-cell design generally render application of such hollow-core fibres difficult in the femtosecond range12. Therefore, no fibre-based concept can currently provide guiding of sub-100 fs pulses over extended distances. By introducing a radial chirp into the photonic crystal, we here demonstrate a novel concept for photonic-crystal fibres that breaks with the paradigm of lattice homogeneity and enables a new degree of freedom in photonic-crystal-fibre design, eliminating much of the pulse duration restriction of earlier approaches.
|Julkaisija||Tampere University of Technology|