實驗名稱:可調諧激(ji)光器解調實驗(yan)
研究方向:光纖光柵傳感、可調諧激光
實驗目的:基于使用光譜(pu)儀解(jie)調(diao)(diao)的(de)Buneman頻率估計(ji)解(jie)調(diao)(diao)算法(fa),編寫了一種(zhong)適用于可(ke)調(diao)(diao)諧(xie)激光器(qi)解(jie)調(diao)(diao)法(fa)的(de)解(jie)調(diao)(diao)程序作(zuo)為解(jie)調(diao)(diao)結(jie)果(guo)(guo)的(de)對(dui)比(bi)(bi);分(fen)析(xi)(xi)了快速(su)可(ke)調(diao)(diao)諧(xie)激光光源FBG解(jie)調(diao)(diao),數據采集延時(shi)影(ying)(ying)響解(jie)調(diao)(diao)精度的(de)問題和采樣(yang)值跳變影(ying)(ying)響解(jie)調(diao)(diao)結(jie)果(guo)(guo)的(de)問題。通過仿真(zhen)和實(shi)驗證實(shi)了該解(jie)調(diao)(diao)算法(fa)的(de)理論分(fen)析(xi)(xi)結(jie)果(guo)(guo),對(dui)兩(liang)種(zhong)算法(fa)進(jin)行了對(dui)比(bi)(bi)。
測試設備:信號發生(sheng)器(qi)(qi),ATA-105功率放大(da)器(qi)(qi),激(ji)光(guang)光(guang)源(yuan)、光(guang)纖光(guang)柵傳感(gan)器(qi)(qi)、壓電陶瓷(ci)等。
實驗過程:本(ben)次(ci)實驗(yan)(yan)使(shi)用ATA-105功率放大器(qi)驅動(dong)(dong)(dong)(dong)(dong)(dong)的(de)(de)壓電(dian)陶瓷(ci)(PZT)提供振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong)信號(hao),實驗(yan)(yan)時用樹(shu)脂將FBG傳(chuan)(chuan)感器(qi)一固定(ding)在PZT上(shang)進(jin)行實驗(yan)(yan)。PZT傳(chuan)(chuan)感器(qi)主要利(li)用壓電(dian)陶瓷(ci)振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong)時對光(guang)(guang)(guang)纖光(guang)(guang)(guang)柵施加的(de)(de)軸(zhou)向(xiang)應變(bian),導(dao)致(zhi)中(zhong)心(xin)波長漂移(yi)的(de)(de)現象來檢測振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong)信號(hao),其中(zhong)光(guang)(guang)(guang)纖光(guang)(guang)(guang)柵傳(chuan)(chuan)感器(qi)是核心(xin)部件,振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong)臺振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong)時會帶(dai)動(dong)(dong)(dong)(dong)(dong)(dong)質量(liang)塊(kuai)發生振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong),質量(liang)塊(kuai)端的(de)(de)振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong)使(shi)得附著在鋼(gang)制懸臂梁上(shang)的(de)(de)光(guang)(guang)(guang)纖光(guang)(guang)(guang)柵發生軸(zhou)向(xiang)應變(bian),進(jin)而產(chan)生中(zhong)心(xin)波長的(de)(de)漂移(yi)。通過檢測中(zhong)心(xin)波長的(de)(de)變(bian)化,來獲得振(zhen)(zhen)動(dong)(dong)(dong)(dong)(dong)(dong)本(ben)身的(de)(de)相關參(can)數。
圖一實驗的硬件系統
實(shi)(shi)驗(yan)(yan)(yan)裝(zhuang)置(zhi):由信號發生器(qi)(qi)(qi)(qi)(qi)(qi)、功(gong)率放大器(qi)(qi)(qi)(qi)(qi)(qi)、壓電(dian)陶瓷、光(guang)(guang)(guang)(guang)柵(zha)傳感(gan)(gan)器(qi)(qi)(qi)(qi)(qi)(qi)和(he)(he)軟件(jian)系統等(deng),本實(shi)(shi)驗(yan)(yan)(yan)采(cai)用是粘貼(tie)式(shi)(shi)振(zhen)(zhen)動傳感(gan)(gan)器(qi)(qi)(qi)(qi)(qi)(qi)和(he)(he)懸臂梁式(shi)(shi)振(zhen)(zhen)動傳感(gan)(gan)器(qi)(qi)(qi)(qi)(qi)(qi),,軟件(jian)系統使(shi)用的(de)(de)是本文編寫(xie)的(de)(de)快速可(ke)調諧激(ji)光(guang)(guang)(guang)(guang)光(guang)(guang)(guang)(guang)源多點(dian)采(cai)樣光(guang)(guang)(guang)(guang)纖(xian)光(guang)(guang)(guang)(guang)柵(zha)解調算法軟件(jian)。同時在第(di)二通(tong)(tong)道(dao)采(cai)用經過(guo)本實(shi)(shi)驗(yan)(yan)(yan)適(shi)配可(ke)調諧激(ji)光(guang)(guang)(guang)(guang)器(qi)(qi)(qi)(qi)(qi)(qi)的(de)(de)Buneman頻(pin)(pin)率估計FBG解調程序(xu)。雙通(tong)(tong)道(dao)解調,對校正后的(de)(de)解調結果(guo)進行對比顯示和(he)(he)分(fen)析。光(guang)(guang)(guang)(guang)纖(xian)光(guang)(guang)(guang)(guang)柵(zha)傳感(gan)(gan)器(qi)(qi)(qi)(qi)(qi)(qi)通(tong)(tong)過(guo)檢測(ce)(ce)其光(guang)(guang)(guang)(guang)譜(pu)反射(she)峰的(de)(de)位(wei)置(zhi)變化(hua)(hua),來(lai)檢測(ce)(ce)被測(ce)(ce)量變化(hua)(hua)。本實(shi)(shi)驗(yan)(yan)(yan)中采(cai)用的(de)(de)三個FBG傳感(gan)(gan)器(qi)(qi)(qi)(qi)(qi)(qi)分(fen)別進行壓電(dian)陶瓷高(gao)頻(pin)(pin)振(zhen)(zhen)動實(shi)(shi)驗(yan)(yan)(yan),激(ji)振(zhen)(zhen)器(qi)(qi)(qi)(qi)(qi)(qi)低頻(pin)(pin)振(zhen)(zhen)動實(shi)(shi)驗(yan)(yan)(yan)和(he)(he)激(ji)振(zhen)(zhen)器(qi)(qi)(qi)(qi)(qi)(qi)加速度實(shi)(shi)驗(yan)(yan)(yan)。實(shi)(shi)驗(yan)(yan)(yan)光(guang)(guang)(guang)(guang)源是調制光(guang)(guang)(guang)(guang)柵(zha)Y分(fen)支(MG-Y)可(ke)調諧半導體激(ji)光(guang)(guang)(guang)(guang)器(qi)(qi)(qi)(qi)(qi)(qi)。這種(zhong)激(ji)光(guang)(guang)(guang)(guang)器(qi)(qi)(qi)(qi)(qi)(qi)本質上是一種(zhong)基于(yu)游標(biao)調諧原理的(de)(de)單(dan)片(pian)集成分(fen)布式(shi)(shi)布拉(la)格反射(she)(DBR)激(ji)光(guang)(guang)(guang)(guang)器(qi)(qi)(qi)(qi)(qi)(qi)。
圖二兩種振動試驗傳感器(qi)設計
實驗結果:振動實驗(yan)五頻輸出采(cai)樣(yang)值變(bian)化和解調結果如下:
圖三3500mv信(xin)號強(qiang)度-60hz振動頻率的情況下五個固定波長(chang)處(chu)的反射譜采樣值
利用傳感(gan)器(qi)一和(he)傳感(gan)器(qi)二進(jin)(jin)行(xing)了多次重復的振(zhen)動實(shi)驗(yan)(yan)。針(zhen)對(dui)傳感(gan)器(qi)一本實(shi)驗(yan)(yan)選(xuan)擇以0.096nm的采樣間隔對(dui)高速振(zhen)動信(xin)號進(jin)(jin)行(xing)采樣,并(bing)依據采樣數據進(jin)(jin)行(xing)了Buneman頻率估計解調(diao)和(he)本文的多點采樣解調(diao)。最后將(jiang)兩者得到的結果進(jin)(jin)行(xing)對(dui)比,經(jing)過處理后得到如(ru)下圖:
圖四壓(ya)電陶瓷7khz-2V高頻振動實驗0.096nm間隔采樣解調結果(guo)對比
圖(tu)五壓(ya)電陶瓷8khz-2V高(gao)頻振動實驗0.096nm間(jian)隔采樣解調結果對比
從圖(tu)四圖(tu)五(wu)可(ke)以看出(chu)(chu),隨著信號強(qiang)度(du)的增加,中心波長的振動幅度(du)也在增大。本實驗提出(chu)(chu)的快(kuai)速可(ke)調(diao)諧激光(guang)光(guang)源(yuan)多(duo)點(dian)采樣光(guang)纖光(guang)柵(zha)解(jie)調(diao)算(suan)法(fa)相較于(yu)Buneman頻率估計解(jie)調(diao)算(suan)法(fa)在具有更高的解(jie)調(diao)范圍(wei)和解(jie)調(diao)精(jing)度(du)。同時在寬采樣間隔(ge)的解(jie)調(diao)中,更能體(ti)現出(chu)(chu)這(zhe)種算(suan)法(fa)的大范圍(wei)、高精(jing)度(du)、高穩(wen)定(ding)性等(deng)優勢。