Kagome结构空心光子光纤轴向气压分布对光场传输的影响研究

Recent progress in the development of the hollow-core photonic crystal fiber(HC-PCF) has led to the investigation of the efficient emission of dispersive waves in the deep-UV region from the Ar-filled Kagome-lattice HC-PCF pumped by femtosecond pulses,which is differ from the supercontinuum generation in a solid-core photonic crystal fiber. The wavelength of the emitted deep-UV light is tunable by easily adjust the pumping pulse energy or the gas pressure, making the system an ideal candidate for applications in various nonlinear experiments that involve propagation of ultrashort optical pulses. But to date, the optical field propagation mechanism is still under discussion. The research work today mainly focus on the new phenomenons with other filled gas or fluid. The axial pressure distribution can efficiently effect the nonlinear refraction index and wavevector, but research works upon this point have not seen yet. This project try to introduce the gas pressure distribution to the Kagome-lattice HC-PCF ultrafast optical field propagation mechanism, analysis the possible influence to the higher soliton orders, higher compression factors, steeper trailing edges and other parameters. This project also try to discuss the possibility of improving the deep-UV conversion efficiency, with the purpose of getting better understanding of the Ar-filled Kagome-lattice HC-PCF and better usage in the demanded applications.

近年研究发现，采用飞秒激光泵浦Ar气填充的Kagome结构空心光子光纤会在深紫外波段产生飞秒色散波，且波长可以简单的通过气压和泵浦能量来进行控制。这种现象具有广泛的应用前景，但其光场传输理论尚不完善。目前的研究工作主要集中在采用不同的流体进行填充，以期发现新的现象和完善理论模型。流体压强的轴向分布直接影响到非线性折射率的轴向分布和轴向波矢等参数，有可能产生新的现象，但目前尚未见基于此角度的研究工作。本项目试图在现有的Kagome结构空心光子光纤超快光场传输近似理论模型中引入轴向气压分布因素，分析其可能的对于高阶光孤子和脉冲自陡峭等方面的影响，完善Kagome结构空心光子光纤的理论模型，并通过建立轴向气压梯度分布进行实验验证，尝试理论分析轴向气压周期性分布等其他分布条件下可能产生的新特性和现象，探讨更高效率产生飞秒深紫外光的可能性，为更好的研究和应用奠定基础。

飞秒激光泵浦气体填充的Kagome结构空心光子光纤会在深紫外波段产生飞秒色散波，且波长可以简单的通过气压和泵浦能量来进行控制，目前的研究工作在流体压强存在轴向分布的条件下开展较少。本项目在现有的Kagome结构空心光子光纤超快光场传输近似理论模型中引入轴向气压分布因素，研究非线性参数的分布及对输出特性的影响，并通过建立轴向气压梯度分布进行实验验证；模拟和实验均表明，随着输入激光脉冲的功率增加，非线性效应加强，输出超连续谱的主峰逐渐向短波方向移动，可以有效的达到紫外和深紫外波段。同时项目设计轴向气压周期性分布等其他实验条件，研究对输出的影响；但周期性温度场引起的轴向气压分布由于气体密闭的原因，在非线性参数变化和对输出影响方面不同于轴向气压梯度分布。项目探索更高效率产生飞秒深紫外光以及飞秒深紫外光放大的可能性，为深紫外光在光谱、检测和可能的放大后进行微加工等应用建立基础。.项目已录用待发表期刊论文共4篇，其中EI收录3篇，中文核心1篇；申请实验设备和模块相关实用新型和发明专利共4项，获得授权1项，3项已受理。