改变光栅拉力实现双峰滤波器的方法研究

Research on dual-wavelength FBG filter by changing the stretch applied on fiber

利用光纤布拉格光栅(FBG)的轴向应力调谐特性,基于一个均匀相位模板,制作了不同波长间隔的双峰(DW)滤波器。通过滑轮将重力转化为光栅的轴向拉力,改变两次曝光时光栅的轴向拉力,制作了波长间隔分别为0.235、0.312、0.558和1.120nm的DW滤波器,拟合得到了重力差与波长间隔的关系。实际制作DW滤波器的波长间隔接近理论值,而且DW的反射谱和透射谱具有很好的一致性。本文方法具有实现简单、设计灵活和成本低的优点,有很好的应用价值。

According to fiber grating＇ s axial stretch tuning properties, dual-wavelength （DW） fiber Bragg gratings （FBGs） with different channel spacings are fabricated based on a uniform phase mask. DW fil- ters with channel spacing of 0. 235 nm,0. 312 nm,0. 558 nrn and 1.12 nm are fabricated respectively by adjusting the stretch which is switched from gravity with the help of a wheel. The relationship between channel spacing and gravity difference is achieved by fitting experiment data, which is close to the theory analysis. The reflectivity spectrum and transmission spectrum of fabricated DW filter show a good agree- ment, which is useful for application. This method has the advantages of simple implementation, flexible wavelength design and low-cost fabrication.