PHOTONIC CRYSTAL WAVEGUIDES AND SYSTEMS USING SUCH WAVEGUIDES

In general, in one aspect, the invention features an apparatus that includes a photonic crystal fiber (200, 900) configured to guide a mode of electromagnetic radiation at a wavelength, lambda, along a waveguide axis. The fiber includes a core (210) extending along the waveguide axis, and a confinement region (220, 910) extending along the waveguide axis and surrounding the core (210). The confinement region (220, 910) includes alternating layers (211-219, 920-922) of a first and a second dielectric material having thicknesses d1 and d2 and different refractive indices n1 and n2, respectively. The thickness of at least one of the alternating layers of the first material differs from thickness d1 or at least one of the alternating layers of the second material differs from thickness d2, where d1 and d2 correspond to a quarter-wave condition for the two dielectric materials given by Formula (I) and Formula (II), respectively. The photonic crystal fiber has an attenuation for the guided mode at the wavelength lambda that is reduced by a factor of about two or more relative to an attenuation for a reference fiber that is identical to the photonic crystal fiber except that the reference fiber has alternating layer thicknesses corresponding to the quarter-wave condition. Un aspect de cette invention se rapporte, de manière générale, à un dispositif qui comprend un fibre (200, 900) à cristaux photoniques qui présente une configuration permettant de guider un mode de rayonnement électromagnétique à une longueur d'onde