Bragg光栅辅助非对称双芯光纤耦合器的研究

利用耦合模理论,推导出了其中一个纤芯写有Bragg光栅的双芯光纤耦合器的完整的耦合模方程。并通过打靶法和Broyden叠代数值解此耦合模微分方程组,分析了在不同失配条件下,双芯光纤耦合器各个端口的输出特性。得到了双芯光纤最佳的失配条件,在此条件下,光栅谐振波长处信号具有优异的反射特性,其他波长的信号则基本不发生耦合,接近无损地通过,此种耦合器具有非常小的插入损耗,是WDM系统中分插复用器的极佳选择。

Study of Bragg Grating Assisted Asymmetric Twin-Core Fiber Coupler

The integrated couple mode equations of the mismatched twin core fiber coupler with Bragg grating written on one core are presented through use of the couple mode theory (CMT). To solve the differential equations, the shooting method and Broyden Iteration method are used, and the output characteristics of the twin core fiber coupler are calculated under different mismatching conditions. The best mismatching condition is derived from the integrated couple mode equations. The mismatched coupler has high reflectivity at the resonance wavelength of Bragg grating and few energy is coupled to the other cores at other wavelengths deviated from the resonance wavelength. This mismatched coupler has small insert loss, which is a novel and potential add/drop filter for use in wavelength-division-multiplexing (WDM) optical fiber systems.