(西南交通大學(xué)　1.信息科學(xué)與技術(shù)學(xué)院；2. 光通信與光器件實(shí)驗(yàn)室，四川　成都 610031)
摘? 要：以Santec公司OVA-650可變光衰減模塊為設(shè)計對象，設(shè)計制作用戶可控制數(shù)字光衰減器。分析OVA-650的衰減原理，建立測試系統(tǒng), 確定步進(jìn)電機(jī)移動步數(shù)與衰減量之間的關(guān)系。測試OVA-650內(nèi)部衰減量與反饋電壓之間的對應(yīng)關(guān)系并建立衰減量與電壓的對換表，采用Matlab進(jìn)行數(shù)值分析及曲線擬合，得到衰減量與電壓關(guān)系的真實(shí)曲線，建立對應(yīng)關(guān)系。建立用戶控制系統(tǒng)，鍵盤輸入用戶想得到的衰減量。本設(shè)計采用二相八拍控制步進(jìn)電機(jī)，選擇12位模數(shù)轉(zhuǎn)換芯片MAX197,并采用自適應(yīng)環(huán)路算法，精確定位到鍵盤輸入的衰減量，可控制范圍為0～35dB，整個系統(tǒng)誤差控制在±0.1dB以內(nèi)，液晶顯示到0.01dB。
關(guān)鍵詞：可變光衰減器；OVA-650；步進(jìn)電機(jī)；
中圖分類號：TN914.52??? 文獻(xiàn)標(biāo)識碼：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;
可變光衰減器(VOA)是光通信系統(tǒng)中重要的光器件之一,其主要功能是完成光信號的功率限制與多路光信號的功率均衡,在光纖網(wǎng)絡(luò)和系統(tǒng)中起到功率管理的作用,用來使整個網(wǎng)絡(luò)中的功率電平保持一定,使光通信網(wǎng)絡(luò)更加智能化且更具靈活性。VOA對DWDM光纖網(wǎng)的重要意義在于: VOA能夠在光學(xué)層(Optical Domain)實(shí)現(xiàn)對光網(wǎng)絡(luò)的全面遠(yuǎn)程控制[1]。到目前為止，光衰減器已形成了固定式、步進(jìn)可調(diào)式、連續(xù)可調(diào)式、及智能光衰減器四種系列。按光衰減器的工作原理可分為位移型光衰減器、直接鍍膜型光衰減器、衰減片型光衰減器、液晶型光衰減器。