Numerical stuides on build-up of self-staring KLM lasers without aperture

• Main Authors: Yen-Ching Chen, 陳延慶
• Other Authors: Wen-Feng Hsieh
• Format: Others
• Language: zh-TW
• Published: 1995
• Online Access: http://ndltd.ncl.edu.tw/handle/27337254491547676520

碩士 === 國立交通大學 === 光電(科學)研究所 === 83 === In this thesis, we have established a numerical model of kerr lens mode-locking(KLM) Ti:sapphire laser cavity by ABCD matrix. In this model, we can simultaneously consider the spatial and temporal effects including self-focusing, gain guiding, free space propagation, group velocity dispersion (GVD), bandwidth limiting, near resonance phase shift, nonlinear absorption and self-phase modulation (SPM). At first, We obtained a solution of a stable cavity, then modified the term of gain saturation to simulate the pulse grown of this laser by assumming CW mode and KLM mode coexisting. We found that there is a turing point in the time evolution of output pulsewidth, where GVD optimally compensates SPM to achieve the limitation of pulse compression. In consequence of self-focusing, the gain of KLM mode becomes larger than that of CW mode, and the pulse is further compressed by the rise of pulse energy. Finally, the KLM mode drains out all of the energy stored in the gain medium and quenchs CW mode, a steady-state solution of mode-locked pulse train is obtained.