Nonlinear dynamic of picosecond pulse propagation in atmospheric air-filled hollow core fibers.
Nonlinear dynamic of picosecond pulse propagation in atmospheric air-filled hollow core fibers.
复制标题
大气填充空心光纤中皮秒脉冲传播的非线性动力学。
DOI：
10.1364/oe.26.008866
复制
发表时间：
2018
期刊：
影响因子：
3.8
通讯作者：
F. Poletti
中科院分区：
文献类型：
--
作者：
S. A. Mousavi;H. C. Mulvad;N. Wheeler;P. Horák;J. Hayes;Yong Chen;T. Bradley;S. Alam;S. Sandoghchi;E. N. Fokoua;D. Richardson;F. Poletti
大气充气空心芯（HC）光纤是一种最简单、最可靠的充气空心芯光纤，它具有显著的非线性特性，在脉冲压缩、频率转换和超连续介质产生等方面有着广泛的应用。虽然亚皮秒和几百皮秒脉冲在充满空气的光纤中的传播已经得到了很好的研究，但空气对持续时间为几皮秒的脉冲的非线性响应具有有趣的特征，尚未得到充分的探索。本文从实验和理论两方面研究了~ 6ps脉冲在三种不同类型的大气充气HC光纤中的非线性传输。有了这个脉冲长度，我们就可以探索不同功率水平下空气的不同非线性特性。利用内部制造的、最先进的HC光子带隙、HC管状和HC kagom<s:1>光纤，我们能够将这些光纤中初始脉冲展宽过程的起源与低功率水平下的旋转拉曼散射（RRS）联系起来。由于我们使用的HC kagom<s:1>光纤的宽带和低损耗传输窗口，我们观察到从低功率下的初始脉冲展宽（通过RRS），通过振动拉曼散射的远程频率转换（2330 cm-1），到高功率下宽带（~700 nm）超连续谱产生的转变。为了以统一的方法模拟如此广泛的非线性过程，我们在广义非线性薛定谔方程中实现了空气的半量子模型，该模型超越了在该脉冲长度范围内常见的单阻尼振荡器模型的限制。通过与实验结果的对比，验证了该模型的有效性，为充气HC纤维非线性过程的设计、建模和优化提供了有力的工具。
Atmospheric air-filled hollow core (HC) fibers, representing the simplest yet reliable form of gas-filled hollow core fiber, show remarkable nonlinear properties and have several interesting applications such as pulse compression, frequency conversion and supercontinuum generation. Although the propagation of sub-picosecond and few hundred picosecond pulses are well-studied in air-filled fibers, the nonlinear response of air to pulses with a duration of a few picoseconds has interesting features that have not yet been explored fully. Here, we experimentally and theoretically study the nonlinear propagation of ~6 ps pulses in three different types of atmospheric air-filled HC fiber. With this pulse length, we were able to explore different nonlinear characteristics of air at different power levels. Using in-house-fabricated, state-of-the-art HC photonic bandgap, HC tubular and HC Kagomé fibers, we were able to associate the origin of the initial pulse broadening process in these fibers to rotational Raman scattering (RRS) at low power levels. Due to the broadband and low loss transmission window of the HC Kagomé fiber we used, we observed the transition from initial pulse broadening (by RRS) at lower powers, through long-range frequency conversion (2330 cm-1) with the help of vibrational Raman scattering, to broadband (~700 nm) supercontinuum generation at high power levels. To model such a wide range of nonlinear processes in a unified approach, we have implemented a semi-quantum model for air into the generalized nonlinear Schrodinger equation, which surpasses the limits of the common single damping oscillator model in this pulse length regime. The model has been validated by comparison with experimental results and provides a powerful tool for the design, modeling and optimization of nonlinear processes in air-filled HC fibers.