Abstract

In this communication, we show the first depressed-core-index photonic-band-gap (DCI-PBG) fibre manufactured by means of the classical MCVD technique. It has been designed to propagate a robust zero dispersion single mode at wavelengths as short as 1μm. The main applications deal with non-linear optics: soliton propagation, parametric amplification and oscillators. This fibre consists in a low-index cylindrical core surrounded by a cladding made of layers with alternating high and low indices, which values are higher than that of the core (figure 1). It has been theoretically demonstrated in a previous paper that such a fibre can propagate one single guided mode [1]. We have designed the DCI-PBG fibre for simultaneously obtaining a suitable coupling to standard fibres and achieving a zero dispersion at λ₀ = 1.06μm by the aim of a two dimensions scalar cylindrical finite-difference beam propagation method (2D FD-BPM) associated to the Wijnand's method [2]. The chromatic dispersion of the guided mode will be presented at the conference. Experimentally, a beam from a CW YLF solid state laser operating at λ₀ = 1.053μm was launched into a lm length of fibre. Figure 2 is the near field observed at the output when the input beam is properly focused on to the central core. The guiding is made possible into the core thanks to the transverse photonic band gap effect. The actual profile of the DCI-PBG fibre and guidance properties will be presented and discussed during the conference.

© 2000 IEEE