光学
曲率
梁(结构)
物理
高斯光束
非线性系统
平方米
光纤
职位(财务)
光束直径
纤维
不稳定性
高斯分布
激光束质量
数学
机械
材料科学
几何学
激光器
量子力学
激光束
经济
复合材料
财务
作者
Amira S. Ahsan,Govind P. Agrawal
出处
期刊:Journal of The Optical Society of America B-optical Physics
[Optica Publishing Group]
日期:2020-01-27
卷期号:37 (3): 858-858
被引量:4
摘要
We present a general framework capable of describing the nonlinear propagation of pulsed optical beams of arbitrary shapes and phase fronts inside a graded-index (GRIN) fiber. The main assumption made is that the spatial self-imaging features of the beam are not affected by the temporal evolution of optical pulses. A propagation kernel known from the work done in the 1970s is used to obtain a distance-dependent nonlinear coefficient that captures all spatial effects within an effective nonlinear Schrödinger equation. We consider three specific beam shapes (Gaussian, circular, and square) to study the impact of the shape, position, and curvature of optical beams on the complex spatiotemporal dynamics specific to GRIN fibers. In particular, we focus on the impact of an input beam’s shape on the modulation-instability sidebands and the generation of multiple dispersive waves when higher-order solitons form inside a GRIN fiber. The results of our numerical analysis indicate that for beam widths chosen to yield the same value of the effective mode area at the input end of the fiber, the nonlinear effects are pronounced considerably when a Gaussian beam is launched into the fiber. We also found that even though the self-imaging period is doubled when an off-centered Gaussian beam is launched into a GRIN fiber, it does not affect the nonlinear evolution because the effective beam area still maintains the same periodicity, as long as the shift in the beam’s center is not so large that it does not remain confined to the fiber’s core.
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