Zolnacz Kinga, Napiorkowski Maciej, Kiczor Anna, Makara Mariusz, Mergo Pawel, Urbanczyk Waclaw
Opt Lett. 2020 Apr 1;45(7):1595-1598. doi: 10.1364/OL.388866.
We report on a new type of long-period-grating generated in a helical core fiber by bending. The grating arises from bend-induced modulation of an equivalent refractive index in the helical core with a period equal to the helix pitch. We experimentally demonstrate that such grating induces multiple resonant couplings between the fundamental modes guided in the central core and the helical side-core. We have also shown that by varying a direction of bending, one can generate the phase shifted grating. The experimental results are supported by numerical simulations based on the coupled mode equations.
我们报道了一种通过弯曲在螺旋芯光纤中产生的新型长周期光栅。该光栅由螺旋芯中等效折射率的弯曲诱导调制产生，其周期等于螺旋节距。我们通过实验证明，这种光栅会在中心芯和螺旋侧芯中引导的基模之间引发多重共振耦合。我们还表明，通过改变弯曲方向，可以产生相移光栅。实验结果得到了基于耦合模方程的数值模拟的支持。
