Passively Mode-Locked Fiber Laser And Its Dispersion Management

The short pulse has widespread applications in areas such as industry, medicine and communication. Passively mode-locked fiber laser and its dispersion management are studied in this article. The main contents are outlined as follows:1. Pulse's propagation in fiber with dispersion management is simulated with the numerical methodology of the nonlinear Schr?dinger equation. We studied: (a)The evolvement processes of the mode-locked pulses with different initial peak power and net cavity dispersions;(b) The adiabatic compression of soliton in dispersion-decreasing fiber(DDL).2. We constructed an all-normal-dispersion ytterbium-doped linear-cavity fiber laser mode-locked by a semiconductor saturable absorber mirror (SESAM). Without anomalous dispersion part, output pulses were highly-chirped and fundamental repetition rate was 435.6 kHz. Three mode-locking states were observed by adjusting polarization controller and pump power. Characters of these states, such as spectrum, pulse shape and stability, are analyzed in control experiments. For comparison, we incorporate carbon nanotubes on the silver mirror as saturable absorber and Er-doped mode-locked fiber laser is realized.3. We constructed a dispersion compensation module with gratings, and did some control experiments about in-cavity dispersion compensation and out-cavity pulse compression. The methodology of using gratings is also generalized.