MEMS可调谐平顶窄带光学滤波器

MEMS-based tunable flat-top narrow-band optical filter

设计了一种基于MEMS技术的可调谐光学滤波器,它通过光栅将输入的宽带光信号色散展开,以一个MEMS扭镜选择将对应滤波器通带的光信号反射至输出端,从而实现光学滤波和波长调谐功能。滤波器的输入端采用单模光纤,输出端采用多模或者少模光纤,可以实现窄带且平顶的通带特性。经过参数优化,仿真分析得结果显示,采用多模/少摸光纤输出的两种滤波器,其0.5 d B和25 d B带宽分别为0.95 nm/0.29 nm和1.39 nm/0.69 nm,分别满足100 GHz和50 GHz信道间隔的DWDM系统要求。由于输出端采用多模或者少摸光纤,从该滤波器输出的光信号不能继续在单模光纤中传输,只能由光探测器接收,因此该滤波器一般应用于全光网络节点中的下载端口。

A tunable optical filter(TOF) based on MEMS technology was designed. The broadband optical signal was first dispersed by a grating and then the wavelength corresponding to the passband of the TOF was selectively reflected to the output by a MEMS torsion mirror, thus the optical filtering and wavelength tuning functions were realized. A single mode fiber(SMF) was employed as the input and a multimode fiber(MMF) or few mode fiber(FMF) was employed as the output, thus the passband of the TOF was characterized by narrow-band and flat-top. After parameter optimization, the simulation results show that the 0.5 d B and 20 d B bandwidth are 0.95 nm/0.29 nm and 1.39 nm/0.69 nm with MMF and FMF employed, which meet the requirements by DWDM systems of 100 GHz and 50 GHz channel spacing, respectively. The output is MMF or FMF, the optical signal passing through the TOF cannot be further transmitted in SMF. The output can just be received by a photo detector, thus this TOF is usually applied as the outputs of the nodes in all optical network.