Studies On Ultra-short Yb-doped All-fiber Lasers With Dispersion Managed In The Cavity

Ultrashort fiber lasers with high energy outputs, have significant value inindustrial laser processing applications, medical technology, military, scientificresearch and so on.Recently, giant chirp fiber lasers have attracted great interest. Such giant chirpfiber lasers can generate nanosecond pulses with high single pulse energy. Applyingthe lasers into chirped pulse amplification (CPA) systems can simplify the CPAsystems to better exploit the benefits of fiber, particularly great integration and lowloss. Based on the characteristic and the applying value, the main content of thedissertation is theoretical and experimental studies of the giant chirp fiber lasers.The main research works are summarized as follows:1. A review of the characteristic, application and development of ultrashort fiberlasers.2. Introduction of the theory of the fiber lasers and ultrashort pulse generationtechnique. Discussions of different fiber lasers based on the cavity configurationand different ways of passively mode-locking.3. Research of the dispersion management technique. Study of pulse compressionand stretch. Research of the dispersion management devices and thecharacteristics. Discussions of different fiber lasers based on the net dispersion ofthe cavity.4. Research of the advantages and value of the giant chirp fiber lasers. Theoreticalstudy of the giant chirp fiber lasers. Discussions of the present types of giant chirpfiber lasers. Research of the giant chirp measurement technique.5. Experimental study of the giant chirp fiber lasers. Based on the theory, we designand produce a giant chirp fiber laser. With dispersion managed with chirped fibergratings, the giant chirp fiber laser can generate1.27ns，15nJ pulses. Byemploying the chirped fiber gratings with negligible nonlinearity, the single pulseenergy is possible to be further increased. Such giant chirp fiber laser can simplify the CPA systems to increase the amplification efficiency. In addition, thenoise-like mode-locking problem, the stability of giant chirp fiber lasers, way toincrease the single pulse energy and compression of giant chirp pulses arediscussed.