基于二维材料的被动调Q光纤激光器研究

发布时间：2018-06-26 03:42

本文选题：光纤激光器 + 被动调Q　；参考：《电子科技大学》2016年硕士论文

【摘要】：调Q技术是一种获得窄脉宽、高能量激光脉冲的重要技术。与传统的激光器相比,被动调Q光纤激光器由于具有结构紧凑、成本低廉、效率高、散热好等特点而备受人们的青睐,已经在激光加工、生物医药和大容量光通信领域得到了广泛应用。近年来,以石墨烯(Graphene)、过渡金属硫化物(包括层状二硫化钼(MoS2)、层状二硫化钨(WS2)等)以及它们的范德瓦尔斯异质结为代表的二维材料因具有独特的光学、电子学特性而成为了各国科学家关注的焦点。因此,基于二维材料的被动调Q光纤激光器研究具有重要的学术意义和实用价值。本文主要对基于石墨烯、Graphene/MoS2异质结、Graphene/WS2异质结三种二维材料的被动调Q光纤激光器进行了实验研究:1、采用化学气相沉积法(CVD)制备的单层石墨烯作为可饱和吸收体,搭建了可调谐的被动调Q光纤激光器,通过调节腔内的可调谐滤波器,实现了输出脉冲波长在1519~1589nm之间的连续可调,调谐范围达到70nm,分析了波长调谐对输出脉冲的重复频率、脉宽和脉冲能量等特性的影响。当输出脉冲的中心波长在1559.9 nm时,调节泵浦功率,输出脉冲的重复频率范围为8.55 kHz~38.26 kHz,最小脉冲宽度为3.45μs,脉冲能量最大值为138.76 nJ。2、制备了Graphene/MoS2范德瓦尔斯异质结二维材料,实验表征了该材料在1550nm波长处的可饱和吸收特性。构建了基于Graphene/MoS2异质结可饱和吸收体的线形腔被动调Q光纤激光器,获得的输出脉冲的中心波长为1559.97 nm,重复频率在15.53 kHz~45.03 kHz之间可调,最小脉宽为1.36μs,最大脉冲能量为37.7nJ,分析了泵浦功率对输出脉冲特性的影响。3、制备了Graphene/WS2范德瓦尔斯异质结二维材料,实验表征了该材料在1550nm波长处的可饱和吸收特性。搭建了基于Graphene/WS2异质结的可调谐被动调Q光纤激光器,通过调节腔内的可调谐滤波器,实现了输出脉冲波长在1509~1589 nm之间的连续可调,调谐范围达到80nm,分析了波长调谐对输出脉冲的重复频率、脉宽和脉冲能量等特性的影响。当输出脉冲的中心波长在1550 nm时,调节泵浦功率,输出脉冲的重复频率范围为10.81~33.65kHz,最小脉冲宽度为2.33μs,脉冲能量最大值为147.2 nJ。
[Abstract]:Q-switching is an important technique for obtaining narrow pulse width and high energy laser pulse. Compared with the traditional laser, passive Q-switched fiber laser has been widely used in laser processing because of its compact structure, low cost, high efficiency and good heat dissipation. Biomedicine and large-capacity optical communication are widely used. In recent years, graphene, transition metal sulfides (including layered molybdenum disulfide (MoS2), layered tungsten disulfide (WS2), etc.) and their van der Waals heterostructures have been characterized by their unique optical properties. Electronic characteristics have become the focus of scientists all over the world. Therefore, the study of passive Q-switched fiber lasers based on two-dimensional materials has important academic significance and practical value. In this paper, the passive Q-switched fiber laser based on Graphene / MoS2 heterojunction and Graphene / WS2 heterojunction is studied experimentally. The monolayer graphene prepared by chemical vapor deposition (CVD) is used as saturable absorber. A tunable passively Q-switched fiber laser is built. By adjusting the tunable filter in the cavity, the output pulse wavelength is continuously adjustable between 1519~1589nm and the tuning range is up to 70 nm. The repetition rate of the output pulse by wavelength tuning is analyzed. The effect of pulse width and pulse energy. When the central wavelength of the output pulse is at 1559.9 nm, the pump power is adjusted. The repetition frequency range of the output pulse is 8.55 kHz, the minimum pulse width is 3.45 渭 s, and the maximum pulse energy is 138.76 nm J. 2. A two-dimensional heterojunction of Graphene / MoS2 van der Waals heterojunction has been prepared. The saturable absorption of the material at 1550nm wavelength was characterized experimentally. A linear cavity passively Q-switched fiber laser based on the saturated absorber of Graphene / MoS2 heterojunction has been constructed. The central wavelength of the output pulse is 1559.97 nm and the repetition rate is between 15.53 kHz and 45.03 kHz. The minimum pulse width is 1.36 渭 s and the maximum pulse energy is 37.7 nJ. The influence of pump power on the output pulse characteristics is analyzed. A novel two-dimensional Graphene / WS2 van der Waals heterojunction material is prepared. The saturation absorptivity of the material at 1550nm wavelength is experimentally characterized. A tunable passive Q-switched fiber laser based on Graphene / WS2 heterojunction is built. By adjusting the tunable filter in the cavity, the output pulse wavelength of 1509 nm is continuously adjustable. The tuning range is up to 80 nm. The effects of wavelength tuning on the repetition rate, pulse width and pulse energy of the output pulse are analyzed. When the central wavelength of the output pulse is at 1550 nm, the pump power is adjusted, the repetition frequency range of the output pulse is 10.81kHz 33.65kHz, the minimum pulse width is 2.33 渭 s, and the maximum pulse energy is 147.2 NJ.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TN248

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