Dispersion and Nonlinearity Characterization of a Mode-Locked Erbium- Doped Fiber Laser

摘要

This report describes the results of dispersion and nonlinearity experiments of the components required for the development of picosecond passively mode-locked fiber lasers. First, we will summarize the interferometric dispersion measurement technique and results for short lengths of fiber (< 1 meter). We measured dispersion of standard fiber at 16.9 +/- 1.4 ps/nm and Er- doped fiber at 8.5 +/- 1.6 ps/nm at 1550 nm. Next, we measured the group delay of three chirped Bragg gratings using a phase difference method and a tunable laser. These chirped Bragg gratings served as one of the mirrors in the linear fiber laser cavity. Finally, we measured the nonlinearity of five different muhiple quantum well saturable absorbers using a z-scan technique. The saturable absorbers served as the mode-locking mechanism in the passively mode-locked fiber laser. The values of the nonlinear absorption ranged from 1 to 3 cm/W. We also measured the refractive nonlinearity of one of the MQW saturable absorbers to be about -4 x 10 cm/W.