We synchronized two passively mode-locked erbiumdoped fiber lasers using a phase lock loop with a large dynamic range and bandwidth, which is realized by using a novel acoustooptic-modulator-grating scheme. Cross-correlation of the two lasers shows the interlaser jitter is under 2 ps (same as the laser pulse width) for period as long as hours. To prove the quality of phase locking, we apply synchronized lasers in two all-optical network applications, one of which requires the lasers to have the same wavelength and the second requires the lasers to be at different wavelengths. In the single wavelength application, the synchronized lasers drive a cascade of two lowbirefringence, polarization maintaining, optical logic gates with switching timing window of 4 and 5 ps, respectively. We obtain nonlinear transmission of 50% at a switching energy of 8 pJ and contrast ration of 16 dB, which are comparable performance as that obtained using a single laser. In the different wavelength application, we use 0.8 ps pulses to switch 2 ps pulses in a two-wavelength nonlinear optical loop mirror demultiplexer with timing window of 5.5 ps. Stable switching is reached at a efficiency as high as 90% at switching energy of 0.8 pJ, and a contrast ratio of 20 dB. Excellent agreement is found between the experimental data and the simulated results, which exclude the timing jitter.

A 40-km length of optical f iber whose group-velocity dispersion decreases exponentially along its length has been fabricated. We experimentally compare the propagation of picosecond solitons through the dispersiondecreasing f iber with that through a constant-dispersion f iber of the same path-averaged dispersion. For a wide range of input powers, the output pulse widths of the dispersion-decreasing f iber are found to be as short as the input pulse widths, whereas the output pulse widths of the constant-dispersion f iber are signif icantly larger. Numerical simulations of the experiment are performed and are in good agreement with the experimental results.

No abstract

No abstract

No abstract