| 摘要: | 為了獲得高平均功率同調光，可藉由提升TDL架構的pump laser-TDL光轉換效率或是提高seed從MA架構獲得的增益來達成。以中山大學提供的Yb:YAG樣本作增益介質，通過自行設計的激發腔與晶體散熱系統，本論文初步建立了TDL架構與MA架構。對於TDL架構，其在共振腔長度為270 mm、輸出耦合鏡之曲率半徑與反射率分別為500 mm及95%、晶體濃度為13.3 at%時，藉由50 Hz repetition rate、duty cycle 10%，平均功率43.6 W的pump laser能夠有平均輸出功率為22.68 W，slope efficiency為61.3%，pump laser-TDL光轉換效率52%。對於MA架構，建立了二通放大器，使1040 nm、pulse energy 25.68 nJ的seed光能有1.8倍的增益，驗證了在平均功率12.4 W的pump laser，晶體能有1.55×10^21 (cm^(-3))的雷射上能階電子密度。通過二通放大結果，可推估seed laser pulse energy 2.568 μJ，其中心波長改為1030 nm且FWHM 1nm，能在趟數增加至9趟時有最大輸出能量0.5 J。;To achieve high average power coherent light beam, the pump laser-TDL light transfer efficiency of a TDL system or the gain of a MA system should be enhanced. This research builds up a fundamental TDL system and a MA system, which based on the Yb:YAG samples offered by NSYSU as gain medium with self-designed pump cavity and crystal cooling system. For TDL system, this research shows that a 13.3 at.%, 300 μm Yb:YAG with a 270 mm long resonator which output coupler’s radius of curvature and reflectivity is 500 mm and 95%,respectively, pumped by a 50 Hz repetition rate,duty cycle 10%,average power 43.6 W pump laser, can deliver TDL, which average output power comes to 22.68 W and the slope efficiency is 61.3%, the pump laser-TDL light transfer efficiency is 52%. For MA system, a 2-pass amplifier is built to let a 1040 nm, pulse energy 25.68 nJ seed has a 1.8x amplification, which proves that the upper laser level density should be 1.55×10^21 (cm^(-3)) when pumped by an average power 12.4 W pump laser. By the results of 2-pass amplifier, the simulation shows a 9-pass amplifier can amplify the seed laser, which central wavelength is 1030 nm and FWHM 1 nm , pulse energy 2.568 μJ, to 0.5 J. |
