非连续线性啁啾取样布拉格光栅型多信道光纤滤波器的设计

Design of high channel-count optical fiber filters based on sampled Bragg grating with discrete linear chirp structure

介绍了一种基于取样布拉格光纤光栅获得多信道光纤滤波器的方法。通过设计一种非连续阶梯型啁啾取样的布拉格光栅结构,可以分别实现单个信道宽度为50,100和200GHz的光纤滤波器。光纤滤波器的每个信道的宽度几乎完全相同,具有平顶、峭沿和高透射率特点,相邻信道间隔离深度超过28dB,平均插入损失不超过0.1dB,3dB带宽内相位响应起伏在5～30ps。利用介绍的方法制作具有相应非连续线性啁啾系数的全息相位掩模板,易于制作,成本低,重复性好。通过改变相应的光纤光栅参数,可以实现不同信道宽度的,性能稳定、可重复性高的光纤滤波器,在高速光通信系统以及光互连中有着非常好的应用前景。

A novel approach to obtain multi-channel comb filters with various channel bandwidths is presented based on a sampled Bragg grating.A kind of high-channel-count comb filter with channel spacings of 50GHz,100GHz and 200GHz is then fabricated respectively by design of a discretechirped sampled Bragg grating structure like a ladder in grating period.This kind of optical fiber filter is characterized by multiple equalized bands with flat-top steep-edge and high transmittance and its inter-channel isolation is more than 28dB,in-band insertion loss is less than 0.1dB and phase response is between 5～30ps in the 3dB bandwidth.By using proposed approach,the holographic phase mask with discrete-chirped coefficients can be easily prepared in low costs and good repetition.Furthermore,by changing the optical fiber parameters,the optical fiber filters with different channel bandwidths can be implemented in high stability and repetition,which has a good potential in the highspeed optical communication systems and optical interconnects.