ACCURACY OF PHASE SHIFT TECHNIQUE WITH LEDS FOR MEASURING TOTAL DISPERSION IN SINGLEMODE FIBERS

摘要

The phase shift technique for measuring total dispersion coefficient has been described in several publications. Main advantages of using LEDs are the compactness of the set-up and the possibility of measuring at many wavelengths with two sources only. In this summary the main effects determining the accuracy of this method are described. The results presented have been obtained as follows : A theoretical delay-time-versus-wavelength curve was calculated for depressed-cladding and for dispersion-flattened singlemode fibers. This curve was disturbed with random noise and systematic errors. The disturbed curves were fitted through a limited number of points at several wavelengths with different types of curve-fits. The resulting dispersion coefficients at specific wavelenghts were compared with the calculated exact values.