Optics and Quantum Electronics

摘要

In the past several years, we have constructed and improved the operation of mode-locked fiber ring lasers in general, stretched pulse fiber ring lasers operating at 1.5 μm wavelength, in particular. The fiber ring lasers are modelocked via intensity- dependent polarization rotation followed by an analyzer, resulting in an effective saturable absorber action. This mechanism is now known as polarization additve-pulse modelocking (P-APM). In the stretched pulse laser, two segments of fiber are used, one of positive dispersion, the other of negative dispersion, the net dispersion being close to zero. The pulse stretches and contracts alternately as it propagates around the loop. Its average intensity is much lower than its peak intensity, and thus the nonlinear effects in the fiber are greatly reduced.