用于制作FBG的紧凑型准分子激光器的研究

Research of compact excimer laser for producing FBG

248 nm的Kr F准分子激光器在光刻、科研等领域有重要的应用。研制了一台用于刻写光纤布拉格光栅的准分子激光器,设计并完善激光器的机械结构,分析了激光器的均匀放电、预电离等关键技术。通过研究充电电压、工作气体配比和总的工作气体压力对输出激光能量和效率的影响,优化激光器的性能;并对光斑均匀性、光束发散角和能量稳定性进行了测试和计算。该准分子激光器的重复频率为1~50 Hz,最高输出效率达2.0%,单脉冲输出能量最高达360 m J,当工作电压不低于24 k V时,激光输出能量不稳定度小于1.8%。用该激光器作为光源采用静态相位掩模法在光纤内刻写布拉格光栅,并对刻写结果进行分析和讨论。

248 nm KrF excimer lasers have important applications in many areas such as photoetching and scientific research. The excimer laser for writing Fiber Bragg Grating was developed. The mechanical structure was designed and improved, and the key technologies including uniform discharge and preionization were analyzed. The laser performance was optimized by studying the impact of the charging voltage, the gas mixture and the total gas pressure on output energy and efficiency. The beam profile homogeneity, beam divergence angle and energy stability were measured and calculated. The repetition rate of the excimer laser is 1-50 Hz, and the maximal output efficiency is about 2.0%, and the maximal single pulse output energy is up to 360 mJ. The instability of output energy is less than 1.8% with charge voltage above 24 kV. Writing Bragg Grating in optical fiber core with a static phase-mask by the above laser as light source, of which results were analyzed and discussed.