Sharma Manish, Pradhan Prabin, Ung Bora
École de technologie supérieure, Department of Electrical Engineering, Montreal, H3C 1K3, Canada.
Sci Rep. 2019 Feb 21;9(1):2488. doi: 10.1038/s41598-019-39527-1.
We demonstrate a new guiding regime termed endlessly mono-radial, in the proposed annular core photonic crystal fiber (AC-PCF), whereby only modes of the fundamental radial order are supported by the fiber at all input wavelengths. This attribute is of high interest for applications that require the stable and broadband guiding of mono-radial (i.e. doughnut shaped) cylindrical vector beams and vortex beams carrying orbital angular momentum. We further show that one can significantly tailor the chromatic dispersion and optical nonlinearities of the waveguide through proper optimization of the photonic crystal microstructured cladding. The analytical investigation of the remarkable modal properties of the AC-PCF is validated by full-vector simulations. As an example, we performed simulations of the nonlinear fiber propagation of short femtosecond pulses at 835 nm center wavelength and kilowatt-level peak power, which indicate that the AC-PCF represents a promising avenue to investigate the supercontinuum generation of optical vortex light. The proposed fiber design has potential applications in space-division multiplexing, optical sensing and super-resolution microscopy.
我们在提出的环形芯光子晶体光纤（AC-PCF）中展示了一种称为无限单径向的新引导机制，在这种机制下，光纤在所有输入波长下仅支持基本径向阶次的模式。对于需要稳定且宽带引导单径向（即甜甜圈形状）圆柱矢量光束和携带轨道角动量的涡旋光束的应用而言，这一特性具有很高的价值。我们进一步表明，通过对光子晶体微结构包层进行适当优化，可以显著调整波导的色散和光学非线性。对AC-PCF显著模态特性的分析研究通过全矢量模拟得到了验证。例如，我们对中心波长为835nm、峰值功率为千瓦级的短飞秒脉冲在光纤中的非线性传播进行了模拟，结果表明AC-PCF是研究光学涡旋光超连续谱产生的一条有前景的途径。所提出的光纤设计在空分复用、光学传感和超分辨率显微镜方面具有潜在应用。
