本論文是藉著速率方程式分析 2.94 μm Er:YAG 固態雷射的特性，以及模擬 Er:YAG 雷射輸入與輸出的關係。雖然 Er:YAG 雷射屬於四能階系統雷射，卻又和一般三能階或四能階雷射的特性不同，Er:YAG 雷射在2.94 μm 波長，其雷射下能階的生命期比上能階的生命期長，加上特殊的能量轉換機制，造成在某些泵激條件下有量子效率大於一的特性。由於2.94 μm 波長的光位在水的強吸收波段，在生醫方面有很多的應用，譬如雷射採血與雷射美容等，但對於 Er:YAG 固態雷射的研究，大都是二極體雷射連續泵激或者是閃光燈脈衝泵激大尺寸的 Er:YAG 雷射，造價昂貴，我們希望藉著模擬，找出適合小型化雷射的參數，以便將來能做出小型化的 Er:YAG 雷射。In this thesis, we analyzed the characteristics and the relations between its input and output of 2.94 μm Er:YAG solid-state laser using rate equations. Although Er:YAG laser is a four-level laser system, it differs in the characteristics from general three-level and four-level lasers. For the transition at 2.94 μm, the life time of lower laser level is longer than that of upper laser level. Besides, there exists some energy transfer processes which causes the quantum efficiency of laser to be larger than one in certain pump condition. Because the wavelength at 2.94 μm is located at the absorption peak of water, Er:YAG laser has many applications in the biomedical field, for example, laser perforator and laser resurfacing. For the most research of Er:YAG laser so far, the pumping was either by powerful laser diodes or using large size flashlamps. We simulated to find out the suitable laser parameters aiming to develop a miniature Er:YAG laser in the near future.
