Fernandes Gil M, Rocha Ana M, Facão Margarida
Opt Express. 2021 May 10;29(10):14601-14614. doi: 10.1364/OE.421798.
We show that optically induced long-period grating (OLPG) is a particular case of inter-modal Bragg-scattering four-wave mixing (BS-FWM). To carry out such analysis, a vector model for the inter-modal BS-FWM was proposed and further tailored to investigate the energy transfer induced by OLPGs. Both processes, BS-FWM and OLPGs, have been proposed for in-line all-optical mode switching in transmission systems with space-division multiplexing (SDM). In this scope, we demonstrate that the bandwidth of OLPGs is larger than the BS-FWM. Furthermore, we show that OLPG-based mode switching can take place in two windows, if both pump beams are launched near the zero value of the differential mode-group delay, and the central wavelength and the bandwidth of such windows can be tuned by properly adjusting the wavelength and the optical power of the pump beams.
我们表明，光诱导长周期光栅（OLPG）是模式间布拉格散射四波混频（BS-FWM）的一种特殊情况。为了进行此类分析，提出了一种用于模式间BS-FWM的矢量模型，并进一步进行调整以研究由OLPG引起的能量转移。BS-FWM和OLPG这两种过程都已被提出用于具有空分复用（SDM）的传输系统中的在线全光模式切换。在此范围内，我们证明OLPG的带宽大于BS-FWM。此外，我们表明，如果两个泵浦光束都在差分模式群延迟的零值附近发射，基于OLPG的模式切换可以在两个窗口中发生，并且通过适当调整泵浦光束的波长和光功率可以调谐此类窗口的中心波长和带宽。
