一、光衰減器的工作原理是什么
光衰(shuai)減器是能(neng)降低(di)光信號能(neng)量的一種光器件(jian),用于對輸入光功率的調整,從而達到(dao)光路上(shang)所需要的光功率,它的工作原理主(zhu)要有(you)三種:
1、位移原理
利用光(guang)纖的衰(shuai)減(jian)量(liang)隨其對中(zhong)精(jing)度(du)而(er)變化的原理(li),在(zai)對接光(guang)纖時,使(shi)光(guang)纖之(zhi)間(jian)發生(sheng)一定位移,從(cong)而(er)達到衰(shuai)減(jian)一定光(guang)能量(liang)的目的。
2、衰減片原理
直接將具有吸(xi)收(shou)特性的衰(shuai)(shuai)減片(pian)(pian)(pian)固定(ding)在(zai)光路(lu)中,衰(shuai)(shuai)減片(pian)(pian)(pian)采用吸(xi)收(shou)型玻璃(li)(li)片(pian)(pian)(pian)或在(zai)玻璃(li)(li)基片(pian)(pian)(pian)上(shang)鍍吸(xi)收(shou)膜的方法來制作,在(zai)玻璃(li)(li)基片(pian)(pian)(pian)上(shang)蒸鍍透射系數(shu)(或反射系數(shu)變化很小的金屬膜,使(shi)通過(guo)鍍膜玻璃(li)(li)片(pian)(pian)(pian)的光功率(lv)被膜層材(cai)料(liao)吸(xi)收(shou)一(yi)部分,光強(qiang)度受(shou)到衰(shuai)(shuai)減。
3、智能電控原理
通(tong)過(guo)電(dian)路(lu)控(kong)制微(wei)型電(dian)機,帶(dai)動(dong)齒(chi)條(tiao),使濾光(guang)片平移,再將數據編碼盤檢測(ce)到(dao)的實際衰(shuai)減量信號反饋(kui)到(dao)電(dian)路(lu)中進行修正(zheng),從而(er)達到(dao)自(zi)動(dong)驅動(dong)、自(zi)動(dong)檢測(ce)和顯示(shi)光(guang)衰(shuai)減量的目的。
二、光衰減器主要應用了哪些技術
1、空氣隔離技術
光(guang)(guang)(guang)(guang)(guang)在(zai)光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)中(zhong)傳(chuan)輸受(shou)到(dao)(dao)全反射(she)定律(lv)的(de)制(zhi)約(yue),無法散(san)(san)射(she)出來(lai),保(bao)持(chi)強(qiang)度的(de)相對(dui)(dui)穩定。而一(yi)旦其脫離(li)光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian),在(zai)光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)與光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)之間(jian)加入(ru)空氣(qi)間(jian)隔(ge),光(guang)(guang)(guang)(guang)(guang)就(jiu)會散(san)(san)射(she)出去,從(cong)而引起(qi)光(guang)(guang)(guang)(guang)(guang)的(de)衰減(jian)。由(you)于光(guang)(guang)(guang)(guang)(guang)從(cong)普通光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)中(zhong)入(ru)射(she)到(dao)(dao)空氣(qi)中(zhong)散(san)(san)射(she)很(hen)強(qiang),為此要(yao)使衰減(jian)量控制(zhi)一(yi)定的(de)范圍,就(jiu)要(yao)確保(bao)隔(ge)離(li)距離(li)及(ji)保(bao)持(chi)兩端光(guang)(guang)(guang)(guang)(guang)纖(xian)(xian)的(de)對(dui)(dui)準。
2、位移錯位技術
此方法是將2根(gen)光纖的(de)纖芯(xin)進行微量平(ping)移錯位,從而達到(dao)功率損(sun)(sun)耗(hao)的(de)效果。通(tong)過(guo)使(shi)(shi)用(yong)(yong)普(pu)通(tong)尾纖,用(yong)(yong)熔接機將2根(gen)尾纖的(de)纖芯(xin)在錯位的(de)情況下進行熔接工作,使(shi)(shi)光在傳輸過(guo)程中發生偏芯(xin)損(sun)(sun)耗(hao)。
3、衰減光纖技術
根據(ju)金(jin)屬離子對光有吸收作用,研制出(chu)參(can)雜金(jin)屬離子的衰(shuai)(shuai)減光纖,與普通光纖每公(gong)里有衰(shuai)(shuai)減系數一樣(yang),這種衰(shuai)(shuai)減光纖也有固定的衰(shuai)(shuai)減系數,只不過這種衰(shuai)(shuai)減系數不按公(gong)里計算,而是按照毫米計算。
4、固態光衰減技術
空氣隔離和吸收玻璃形式的可調光衰減器都是采用(yong)機(ji)械(xie)式(shi)的方法完成(cheng)衰(shuai)減的可(ke)調(diao)性,也有少(shao)量(liang)的采用(yong)各(ge)種固態光(guang)(guang)(guang)衰(shuai)減技(ji)術,比如可(ke)調(diao)衍射光(guang)(guang)(guang)柵(zha)技(ji)術、MEMS技(ji)術、液晶(jing)技(ji)術、磁光(guang)(guang)(guang)技(ji)術、平面光(guang)(guang)(guang)波導(dao)技(ji)術等。