Majchrowska Sylwia, Żołnacz Kinga, Urbańczyk Wacław, Tarnowski Karol
Opt Lett. 2022 May 15;47(10):2522-2525. doi: 10.1364/OL.456521.
This study investigates the nonlinear frequency conversions between the six polarization modes of a two-mode birefringent fiber. The aim is to demonstrate that the selective excitation of different combinations of linearly polarized spatial modes at the pump wavelength initiates distinct intermodal-vectorial four-wave mixing processes. In particular, this study shows that exciting two orthogonally polarized LP and LP modes can lead to the simultaneous generation of up to three pairs of different spatial modes of orthogonal polarizations at different wavelengths. The role of the phase birefringence of the spatial modes in the phase matching of such a four-wave mixing process is explained. Moreover, the theoretical predictions are verified through numerical simulations based on coupled nonlinear Schrödinger equations, and are also confirmed experimentally in a commercially available birefringent fiber.
本研究探讨了双模双折射光纤的六种偏振模式之间的非线性频率转换。目的是证明在泵浦波长处对不同线性偏振空间模式组合进行选择性激发会引发不同的模间矢量四波混频过程。具体而言，本研究表明，激发两个正交偏振的LP和LP模式可导致在不同波长处同时产生多达三对不同的正交偏振空间模式。解释了空间模式的相位双折射在这种四波混频过程的相位匹配中的作用。此外，通过基于耦合非线性薛定谔方程的数值模拟验证了理论预测，并在商用双折射光纤中进行了实验验证。
