Method of and device for measuring the nonlinear refractive index in a single mode optical fibre

摘要

A train of transform-limited optical pulses with wavelength close to the zero-dispersion wavelength of the fiber and high and variable peak power, such as to give rise to self-phase modulation, is sent into a fiber. The spectral broadening of the signal exiting the fiber is measured for a number of values of the peak power of the pulses and the nonlinear refractive index is obtained from the angular coefficient of the straight line representing spectral broadening versus peak power.