论文标题
使用单相移的99％模式转换带宽的光栅带宽
Tripling the 99 % mode conversion bandwidth of gratings using a single phase shift
论文作者
论文摘要
在强模式转换强度下实现较大的带宽是几种模式光学波导的中心问题。标准模式转换光栅最简单的修改是结合一个额外的间隙。这种简单的设计尚未应用于在任何几种模式波导的核心模式之间扩展转换频谱，例如很少的模式纤维，可能是由于缺乏关键参数控制的知识所致：（a）谐振波长处的相位移位值，以及（b）放置相移的确定方法，该方法适应了在光栅写入过程中波导属性变化的相位变化。从半分析的考虑因素来看，我们完全表明，我们对单相移光的设计将99％转换强度的带宽增加了2.9倍以上，并阐明了至关重要的参数公差。从转换光谱中可以确定相移的位置，从而避免了在光撰写过程中对修改的波导特性的任何估计。这提供了渴望在纤维激光腔和通信系统中分散控制的段落内启动解决方案。
Achieving large bandwidth at strong mode conversion strengths is a central problem in few-mode optical waveguides. The most uncomplicated modification of a standard mode-converting grating is to incorporate a single extra gap. Such simple design has not been applied yet for broadening conversion spectrum between core modes of any few-mode waveguide e.g. few-mode fiber, possibly due to lacking knowledge of critical parameter control: (a) phase shift value at resonance wavelength, and (b) deterministic method for placement of the phase shift(s) accommodating the change in waveguide properties during grating writing. From semi-analytical considerations, we show in full generality that our design of a single-phase-shifted grating increases the bandwidth at 99 % conversion strength by more than 2.9 times, together with elucidating crucial parameter tolerances. The phase-shift placement is determinable on-the-go from the conversion spectra, thereby obviating any estimation of modified waveguide properties during grating-writing. This offers the longed on-demand in-fiber solution for dispersion control in fiber laser cavities and communication systems.
