SESAM Technology And Application In Yb～(3+): Fiber Laser

In this thesis, theoretical and experimental study of Yb3+ doped double-clad mode-locked fiber laser and semiconductor saturable absorber mirror (SESAM) was presented. The main contents are as follows:1. The development and application of femtosecond laser was introduced. A brief introduction on the merits of mode-locked laser and the development of SESAM was presented.2. Detailed analysis of the mode-locking theory of femtosecond fiber laser was given, including the characteristics of stimulated emission of Yb3+-doped fibers and double-clad fiber, and the techniques of mode-locking in those fiber lasers.3. An introduction of SESAM was presented. Material and device parameters including recover times, damage threshold, the saturation intensity of the different SESAM was introduced. We proposed that a higher damage threshold may be achieved with a couple of quarter wavelength coating on the SESAM with alternative SiO2 and ZrO2, while keep modulation depth under control.4. We also made the experimental study on the SESAM samples and some substrates for comparison. The damage threshold of Si, SESAM as grown and etched SESAM were measured with pulse duration of 50fs, 200fs and 400fs respectively, and the damage threshold of those samples were presented.5. The parametric study of Yb3+ doped double-clad fiber laser using two different designs was performed, and the phenomena and results of the experiment was reported. The best effort of the output power was five hundred milliwatt, at the wavelength of 1090nm.6. Finally I give a summery of my work and proposed the future directions.