基于滤光片型可变光衰减器的测试及控制设计

(西南交通大学　1.信息科学与技术学院；2. 光通信与光器件实验室，四川　成都 610031)
摘  要：以Santec公司OVA-650可变光衰减模块为设计对象，设计制作用户可控制数字光衰减器。分析OVA-650的衰减原理，建立测试系统, 确定步进电机移动步数与衰减量之间的关系。测试OVA-650内部衰减量与反馈电压之间的对应关系并建立衰减量与电压的对换表，采用Matlab进行数值分析及曲线拟合，得到衰减量与电压关系的真实曲线，建立对应关系。建立用户控制系统，键盘输入用户想得到的衰减量。本设计采用二相八拍控制步进电机，选择12位模数转换芯片MAX197,并采用自适应环路算法，精确定位到键盘输入的衰减量，可控制范围为0～35dB，整个系统误差控制在±0.1dB以内，液晶显示到0.01dB。
关键词：可变光衰减器；OVA-650；步进电机；
中图分类号：TN914.52    文献标识码：A
Based on the filter type variable optical attenuator test and control design
Qiao Feng1， Luo Bin1,2，Pan Wei1,2
(1.School of Information Science & Technology; 2.Optical Communication And Optical Devices Lab
Southwest Jiaotong University, Chengdu 610031，China)
Abstract: Take OVA-650(Santec corporation) invariable optical attenuator module as the design object, this design establishes user control system.By principle, the establishment of test systems to stepper motor moves and the relationship between the attenuation. OVA-650 testing of internal decay and feedback, pressure and the corresponding relationship between the establishment the voltage and attenuation on the table for using Matlab numerical analysis and curve fitting, and get the real curve, the establishment of corresponding relations. The establishment of user control system, keyboard users want attenuation. This design uses two-phase 8 deadbeat control stepper motor, select 12 analog-digital conversion MAX197 chip, and adaptive loop algorithms, accurate positioning of the keyboard input attenuation Volume control range of 0～35 dB, in the whole system error control within ± 0.1dB, and liquid crystal displays to 0.01 dB.
Key words: Variable Optical Attenuator; OVA-650; stepper motor;
可变光衰减器(VOA)是光通信系统中重要的光器件之一,其主要功能是完成光信号的功率限制与多路光信号的功率均衡,在光纤网络和系统中起到功率管理的作用,用来使整个网络中的功率电平保持一定,使光通信网络更加智能化且更具灵活性。VOA对DWDM光纤网的重要意义在于: VOA能够在光学层(Optical Domain)实现对光网络的全面远程控制[1]。到目前为止，光衰减器已形成了固定式、步进可调式、连续可调式、及智能光衰减器四种系列。按光衰减器的工作原理可分为位移型光衰减器、直接镀膜型光衰减器、衰减片型光衰减器、液晶型光衰减器。