Characterisation of optical pulses travelling through a photonic crystal fibre using Fourier-transform spectral interferometry

摘要

Dispersion properties of a 37 cm long photonic crystal fibre were studied using spectral interferometry. The interferograms were evaluated by the conventional and the windowed Fourier-transform method, as well as other commonly used ones, such as the cosine function fit, the stationary phase point and the minima-maxima methods. It is shown that from the five techniques the conventional Fourier-transform method provided the dispersion coefficients with the highest accuracy, and both Fourier-transform techniques could detect phase jumps in the vicinity of the absorption valleys seen in the transmission spectrum of the fibre. We present a novel simple evaluation procedure based on Fourier-transform for a quick retrieval of the spatial and temporal pulse shape after the fibre. The time delay between the higher and the fundamental transversal modes was also measured by the Fourier-transform method.