基于碲酸盐微结构光纤的超连续光源研究

发布时间：2018-06-08 22:11

本文选题：碲酸盐微结构光纤 + 超连续光源　；参考：《吉林大学》2015年硕士论文

【摘要】：宽波段全光纤超连续光源在前沿科学研究、光通信、环境监测、医疗、国防安全等领域有着重要的应用。尤其在国防安全领域，由于超连续光源不仅具有宽度可达数千纳米的光谱，而且具有高的亮度和相干性，因此可对各类光电探测器进行全谱覆盖和干扰，实现超宽波段范围内的光电对抗。实现宽波段的超连续光源是国际学术界和工业界努力追求的目标。目前，基于石英微结构光纤的0.32m波段超连续光源研究已经趋于成熟。进一步将超连续光源波长拓展到中红外波段,研制波长大于2m的中红外波段超连续相干光源具有非常重要的意义。由于石英光纤的透过窗口相对较窄（仅覆盖0.32.5m波段），这限制了它在中红外波段超连续光源研制中的应用。为了产生中红外波段超连续相干光源,国内外研究者们已经把目光转向了新型的碲酸盐、氟化物和硫化物微结构光纤,这些光纤的光学透过窗口可覆盖中红外波段。其中，由于碲酸盐微结构光纤具有高的非线性系数、较好的热稳定性和化学稳定性、相对较宽的中红外透过窗口，因此它有望被用于研制具有实用化水平的全光纤紧凑型中红外波段超连续光源。尽管目前在基于碲酸盐微结构光纤的超连续光源研究方面已经取得了一定的进展，，但在该方面缺乏系统的研究，而且碲酸盐微结构光纤中的中红外波段光参量过程研究几乎是空白。在攻读硕士期间，作者在基于碲酸盐微结构光纤的超连续光源研究方面进行了系统的研究，取得了以下研究结果。在理论模拟方面我们进行了以下三个方面的研究工作：（1）研究了光纤的结构对光纤色散，非线性系数和有效模场面积等光纤参数的影响。模拟结果表明，纤芯和空气孔尺寸都对光纤的参数有着重要影响，光纤的非线性系数，有效模场面积呈现非单调变化特性。（2）建立了光纤中光脉冲传输的理论模型，利用分步傅里叶法对基于碲酸盐微结构光纤的超连续光源产生进行了系统的理论模拟，综合考虑了光纤结构、光纤长度、色散特性、泵浦激光脉宽、峰值功率等因素，重点讨论了泵浦激光峰值功率、脉冲宽度和纤芯直径对超连续光谱产生的影响。模拟结果表明，对于波长为1560nm的飞秒激光泵浦源，实现宽波段超连续光谱产生的最佳光纤芯径约为3.5μm。（3）对碲酸盐微结构光纤中的宽带可调谐参量光产生进行了一些理论探索工作。理论模拟结果表明，当泵浦光波长为1560nm时，可以获得覆盖2065-2925nm波段的宽调谐参量光产生；当泵浦光波长为2m时，可以获得覆盖3540-4185nm的宽调谐参量光产生。在实验方面，首先我们用棒管法拉制了具有不同纤芯直径的碲酸盐微结构光纤，然后使用1560nm的飞秒脉冲激光泵浦碲酸盐微结构光纤研究了光纤中超连续光谱的产生，探索了泵浦激光峰值功率、光纤长度和纤芯直径等参数对超连续光谱产生的影响。通过优化实验参数，当泵浦激光脉宽为1.2ps，平均功率为725mW，光纤长度为3cm时，获得了覆盖1017-2300nm波段的超连续光源。
[Abstract]:The wide band all fiber supercontinuous light source has an important application in frontier scientific research, optical communication, environmental monitoring, medical treatment, national defense security and other fields. Especially in the field of national defense security, because the supercontinuous light source not only has the spectrum of thousands of nanometers, but also has high brightness and coherence, it can be carried out to all kinds of photodetectors. Full spectrum coverage and interference to realize the optoelectronic countermeasures in the ultra wide band range. The realization of the ultra continuous light source in the wide band is the goal pursued by the international academic and industrial circles. At present, the research on the 0.32m band supercontinuous light source based on the quartz microstructural fiber has become mature. The mid infrared band supercontinuum coherent light source with wavelength greater than 2m is of great significance.
Because the transmission window of the quartz fiber is relatively narrow (covering only the 0.32.5m band), it restricts its application in the development of the super continuous light source in the middle infrared band. In order to produce the super continuous coherent light source in the middle infrared band, the researchers at home and abroad have turned their eyes to the new tellurate, the fluoride and the sulfide microstructural fiber, these fibers. The optical transmission window can cover the middle infrared band, in which the tellurite microstructural fiber has a high nonlinear coefficient, good thermal stability and chemical stability, and a relatively wide mid infrared window. Therefore, it is expected to be used to develop a compact medium infrared supercontinuous light source with a practical level. At present, some progress has been made in the research of supercontinuous light source based on tellurite microstructural fiber, but there is a lack of systematic research in this respect, and the study of the optical parametric process in the middle infrared band of tellurite microstructural fiber is almost blank. During the period of master's study, the author was based on the supercontinuum based on tellurite microstructural fiber. The research of light source has been systematically studied and the following research results have been achieved.
In the field of theoretical simulation, we have carried out the following three aspects: (1) study the influence of fiber structure on fiber dispersion, nonlinear coefficient and effective mode field area. The simulation results show that the core and air hole size have an important influence on the parameters of the fiber, the nonlinear coefficient of the optical fiber, the effective mode scene. The product presents non monotonic characteristics. (2) a theoretical model of optical pulse transmission in optical fiber is established. A systematic theoretical simulation of the production of supercontinuous light source based on tellurite microstructural fiber is carried out by step Fu Liye method. The optical fiber structure, fiber length, dispersion, pump laser pulse width, peak power and other factors are considered. The effect of the peak power of the pumped laser, the pulse width and the diameter of the core on the generation of the supercontinuum is discussed. The simulation results show that the optimum fiber core diameter of the wide band supercontinuum is about 3.5 mu m. (3) for the generation of the Broadband Tunable Parametric light in the tellurite microstructural fiber for the femtosecond laser pumping source with a wavelength of 1560nm. The theoretical simulation results show that when the wavelength of the pump is 1560nm, the wide tuning parametric light can be generated in the 2065-2925nm band. When the wavelength of the pump is 2m, the wide tuning parametric light can be produced to cover the 3540-4185nm.
In the experiment, we first made the tellurite microstructural fiber with different core diameter with the rod tube Fala. Then we use the 1560nm's femtosecond pulse laser to pump tellurite microstructural fiber to study the generation of the supercontinuum in the optical fiber, and explore the peak power of the pump laser, the length of the fiber and the diameter of the core, and the supercontinuous light. By optimizing the experimental parameters, when the pump laser pulse width is 1.2ps, the average power is 725mW and the fiber length is 3cm, the supercontinuous light source covering the 1017-2300nm band is obtained.
【学位授予单位】：吉林大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN253

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