Optical fibre dispersion measurement using colour centre laser

The capabilities of the NaCl:OH colour centre laser for generating picosecond pulses over >150 nm wavelength range makes it an extremely useful tool for measurement of optical fibre dispersion in the 1550 nm wavelength transmission window. A straightforward technique is described for measuring both first and second order group velocity dispersion with better than 0.2% accuracy for kilometre fibre lengths. The technique uses dependence of transmission delay on pulse carrier wavelength, measured with high speed photodetectors. Results are given for measurements on samples of both dispersion-shifted and standard single-mode optical fibre.