偏振光，英文(wen)名：Polarization（偏極化）
偏(pian)振光(guang)在光(guang)學元器件中應用(yong)產品有：偏(pian)光(guang)片(pian)，線偏(pian)光(guang)，圓偏(pian)光(guang)，偏(pian)振鏡(jing)，偏(pian)振分束(shu)(shu)鏡(jing)，起偏(pian)器，檢偏(pian)器，保偏(pian)器，偏(pian)振分束(shu)(shu)膠合棱鏡(jing)，法(fa)拉遞(di)旋(xuan)轉(zhuan)片(pian)，旋(xuan)光(guang)片(pian)，渦(wo)旋(xuan)波片(pian)，單反相(xiang)機鏡(jing)頭CPL濾(lv)鏡(jing)，激光(guang)器旋(xuan)光(guang)器。
自然光(guang)，太陽光(guang)，普通(tong)光(guang)源，面光(guang)源，OLED，LED燈光(guang)叫非偏振光(guang)
太陽(yang)鏡眼(yan)，AR/VR眼(yan)鏡，CCD，COMS，LCD屏，光柵，具(ju)體偏振光的綜(zong)合(he)物(wu)。常常把綜(zong)合(he)光：U=P+S在光學薄膜設計中(zhong)U=Tp+Ts或(huo)(Rp+Rs)，T為透過，R為反射；矢量分(fen)(fen)為P分(fen)(fen)量（Paralled水平或(huo)平行(xing)偏振)和S分(fen)(fen)量(Senkrcht垂直(zhi)偏振）。
自然光
光(guang)(guang)波(bo)(bo)是(shi)橫波(bo)(bo)，即(ji)光(guang)(guang)波(bo)(bo)矢(shi)(shi)量(liang)的(de)(de)(de)(de)振(zhen)(zhen)動方(fang)(fang)向(xiang)垂直(zhi)于(yu)(yu)光(guang)(guang)的(de)(de)(de)(de)傳(chuan)播方(fang)(fang)向(xiang)。通常，光(guang)(guang)源發出的(de)(de)(de)(de)光(guang)(guang)波(bo)(bo)，其光(guang)(guang)波(bo)(bo)矢(shi)(shi)量(liang)的(de)(de)(de)(de)振(zhen)(zhen)動在(zai)垂直(zhi)于(yu)(yu)光(guang)(guang)的(de)(de)(de)(de)傳(chuan)播方(fang)(fang)向(xiang)上作(zuo)無規則取向(xiang)，在(zai)空間內(nei)，光(guang)(guang)波(bo)(bo)矢(shi)(shi)量(liang)的(de)(de)(de)(de)分布(bu)可(ke)看(kan)作(zuo)是(shi)機會均(jun)等的(de)(de)(de)(de)，它們的(de)(de)(de)(de)總(zong)和與光(guang)(guang)的(de)(de)(de)(de)傳(chuan)播方(fang)(fang)向(xiang)是(shi)對稱的(de)(de)(de)(de)，即(ji)光(guang)(guang)矢(shi)(shi)量(liang)具有(you)軸對稱性、均(jun)勻分布(bu)、各(ge)方(fang)(fang)向(xiang)振(zhen)(zhen)動的(de)(de)(de)(de)振(zhen)(zhen)幅相同，這(zhe)種(zhong)光(guang)(guang)就稱為自然光(guang)(guang)。（即(ji)光(guang)(guang)是(shi)散亂無序的(de)(de)(de)(de)，自由派）。
線偏振光
光矢量端點穿越軌跡為(wei)直線，即光矢量只(zhi)沿(yan)著一個確定的方向(xiang)振(zhen)動(dong)，其大小隨相(xiang)位變化(hua)、方向(xiang)不(bu)變，稱為(wei)線偏振(zhen)光。最大特點是雙向(xiang)性偏振(zhen)。
橢圓偏振光
光(guang)(guang)矢(shi)量端點(dian)穿越軌跡為一(yi)橢(tuo)圓，即(ji)光(guang)(guang)矢(shi)量不斷(duan)旋轉，其大小、方向隨(sui)時間有規律的變化。像電(dian)力不穩一(yi)樣，忽(hu)明忽(hu)暗，一(yi)會(hui)兒P光(guang)(guang)，一(yi)會(hui)兒S光(guang)(guang)受(shou)脈沖影響(xiang)還不穩，形成近視(shi)的橢(tuo)圓。
圓偏振光
光矢(shi)量端點穿越(yue)軌(gui)跡為(wei)一圓(yuan)，即光矢(shi)量不斷旋(xuan)轉，其大小不變，但(dan)方向(xiang)(xiang)隨時(shi)間有(you)規律(lv)地變化。部分偏(pian)(pian)振(zhen)(zhen)(zhen)光，像(xiang)個正弦波有(you)周期性翻(fan)滾，最(zui)大特點是(shi)(shi)：單向(xiang)(xiang)性偏(pian)(pian)振(zhen)(zhen)(zhen)。偏(pian)(pian)振(zhen)(zhen)(zhen)片(pian)用途最(zui)廣(guang)的(de)(de)就(jiu)是(shi)(shi)用于LCD的(de)(de)液晶顯示(shi)屏中。所(suo)以，拿一片(pian)祼的(de)(de)偏(pian)(pian)振(zhen)(zhen)(zhen)片(pian)對著(zhu)顯示(shi)器水平或垂直(zhi)或轉某個角度，會發現顯示(shi)器上的(de)(de)圖(tu)案(an)由(you)黑變亮(liang)或由(you)亮(liang)變黑，把該偏(pian)(pian)振(zhen)(zhen)(zhen)片(pian)正反面去測試都相同，這就(jiu)是(shi)(shi)線偏(pian)(pian)振(zhen)(zhen)(zhen)片(pian)（都叫(jiao)線偏(pian)(pian)光），反之只(zhi)有(you)一個面差(cha)別(bie)大，反面差(cha)別(bie)不大就(jiu)是(shi)(shi)圓(yuan)偏(pian)(pian)振(zhen)(zhen)(zhen)片(pian)（都叫(jiao)圓(yuan)偏(pian)(pian)光）。市面上的(de)(de)圓(yuan)偏(pian)(pian)振(zhen)(zhen)(zhen)片(pian)原理就(jiu)是(shi)(shi)，加(jia)了(le)一片(pian)1/4λ的(de)(de)波片(pian)。
什么叫波片?
波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)，又稱為相(xiang)位延遲(chi)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)，因為偏(pian)(pian)(pian)振(zhen)光(guang)(guang)具(ju)(ju)有(you)折射(she)(she)率不同，可(ke)能(neng)用(yong)薄膜定向(xiang)拉伸或(huo)雙折射(she)(she)材料加工(gong)而(er)(er)成(cheng)。使通過(guo)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)的(de)(de)(de)兩個(ge)互相(xiang)正(zheng)交的(de)(de)(de)偏(pian)(pian)(pian)振(zhen)分(fen)量產生相(xiang)位偏(pian)(pian)(pian)移，可(ke)用(yong)來(lai)調整(zheng)光(guang)(guang)束的(de)(de)(de)偏(pian)(pian)(pian)振(zhen)狀(zhuang)態。在(zai)(zai)(zai)光(guang)(guang)學元(yuan)器(qi)件中常(chang)見的(de)(de)(de)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)由(you)石英晶(jing)體制(zhi)作而(er)(er)成(cheng)，主要(yao)為四(si)分(fen)之(zhi)一(yi)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)和二分(fen)之(zhi)一(yi)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)（半波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)）。石英晶(jing)體（也叫人(ren)工(gong)水(shui)晶(jing)或(huo)人(ren)造晶(jing)體）具(ju)(ju)有(you)雙折射(she)(she)率效應，依據X,Y,Z三軸(zhou)方向(xiang)上，定向(xiang)切割的(de)(de)(de)角(jiao)(jiao)度不同，產生的(de)(de)(de)光(guang)(guang)程差不同。四(si)分(fen)之(zhi)一(yi)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)（λ/4波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)）：能(neng)使o光(guang)(guang)和e光(guang)(guang)光(guang)(guang)程差為λ/4的(de)(de)(de)晶(jing)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)。旋轉波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)使入(ru)(ru)射(she)(she)光(guang)(guang)偏(pian)(pian)(pian)振(zhen)方向(xiang)與(yu)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)兩軸(zhou)夾(jia)角(jiao)(jiao)為45°，橢圓(yuan)/圓(yuan)偏(pian)(pian)(pian)振(zhen)光(guang)(guang)經過(guo)四(si)分(fen)之(zhi)一(yi)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)后，變成(cheng)了線偏(pian)(pian)(pian)振(zhen)光(guang)(guang)。同理，如果入(ru)(ru)射(she)(she)光(guang)(guang)偏(pian)(pian)(pian)振(zhen)方向(xiang)與(yu)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)兩軸(zhou)夾(jia)角(jiao)(jiao)為45°，線偏(pian)(pian)(pian)振(zhen)光(guang)(guang)經過(guo)四(si)分(fen)之(zhi)一(yi)波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)后，變成(cheng)了圓(yuan)偏(pian)(pian)(pian)振(zhen)光(guang)(guang)。波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)（或(huo)延遲(chi)板）是具(ju)(ju)有(you)特(te)定雙折射(she)(she)的(de)(de)(de)透(tou)明片(pian)(pian)(pian)(pian)(pian)(pian)(pian)，通常(chang)用(yong)來(lai)控制(zhi)光(guang)(guang)束的(de)(de)(de)偏(pian)(pian)(pian)振(zhen)態。波(bo)(bo)(bo)(bo)(bo)(bo)片(pian)(pian)(pian)(pian)(pian)(pian)(pian)具(ju)(ju)有(you)一(yi)個(ge)快軸(zhou)和一(yi)個(ge)慢軸(zhou)，都(dou)是垂(chui)直于表面和光(guang)(guang)束傳(chuan)播(bo)方向(xiang)的(de)(de)(de)，并且相(xiang)互垂(chui)直。在(zai)(zai)(zai)快軸(zhou)方向(xiang)偏(pian)(pian)(pian)振(zhen)的(de)(de)(de)光(guang)(guang)相(xiang)速度稍大(da)。需要(yao)的(de)(de)(de)光(guang)(guang)延遲(chi)（兩偏(pian)(pian)(pian)振(zhen)方向(xiang)上的(de)(de)(de)相(xiang)位延遲(chi)差）只在(zai)(zai)(zai)有(you)限波(bo)(bo)(bo)(bo)(bo)(bo)長區域和有(you)限入(ru)(ru)射(she)(she)角(jiao)(jiao)范(fan)圍內能(neng)夠(gou)得到。
種類和應用
最常(chang)見的(de)(de)波片(pian)(pian)(pian)是(shi)四分之一波片(pian)(pian)(pian)（λ/4 片(pian)(pian)(pian)）和(he)(he)半(ban)波片(pian)(pian)(pian)（λ/2片(pian)(pian)(pian)），其中(zhong)兩線(xian)偏振方向的(de)(de)相(xiang)位延遲差分別為 π/2和(he)(he)π，對(dui)應的(de)(de)相(xiang)位傳(chuan)播距離分別為λ / 4和(he)(he)λ / 2。
如果光束為(wei)線(xian)偏(pian)(pian)振的，并且偏(pian)(pian)振方(fang)向是沿(yan)著波片的某一個軸，那么偏(pian)(pian)振方(fang)向不改變(bian)。
如果入射的偏振(zhen)態與任一軸(zhou)不重合(he)，波(bo)(bo)片(pian)為半波(bo)(bo)片(pian)，那(nei)(nei)么偏振(zhen)光(guang)仍然(ran)是(shi)線(xian)偏振(zhen)的，但是(shi)偏振(zhen)方向發生旋轉(zhuan)(zhuan)。如果線(xian)偏振(zhen)光(guang)與軸(zhou)夾角(jiao)為 45°，那(nei)(nei)么偏振(zhen)方向旋轉(zhuan)(zhuan)90°。
如果入(ru)射(she)線偏(pian)振(zhen)光與軸之間夾(jia)角為 45°，通過(guo)四分之一波片可以(yi)得(de)到(dao)圓(yuan)偏(pian)振(zhen)光。（其它的線偏(pian)振(zhen)光會變成橢圓(yuan)偏(pian)振(zhen)光。）反過(guo)來(lai)，圓(yuan)偏(pian)振(zhen)光通過(guo)四分之一波片可以(yi)得(de)到(dao)線偏(pian)振(zhen)光。
在(zai)激(ji)光器諧振(zhen)(zhen)腔中，在(zai)增益(yi)介質(zhi)兩邊放置兩個(ge)四分之一(yi)波(bo)片可(ke)以實現單頻(pin)工作（參閱扭曲模技(ji)術）。在(zai)激(ji)光晶體和諧振(zhen)(zhen)腔反射鏡之間放置一(yi)個(ge)半(ban)波(bo)片可(ke)以減小去(qu)極化損耗(hao)。半(ban)波(bo)片和偏振(zhen)(zhen)片結(jie)合使(shi)用(yong)可(ke)以實現可(ke)調(diao)透射率的輸出耦合器。
波片通常由石(shi)英晶體（SiO2）制作，因(yin)為它(ta)在很大的波長范圍(wei)內(nei)具(ju)有(you)很高的透明(ming)度，并且(qie)具(ju)有(you)很高的光學質量。還有(you)一些其它(ta)的材料（應用于(yu)其它(ta)波長范圍(wei)）可以，例(li)如方(fang)解石(shi)（CaCO3），氟化鎂（MgF2），藍寶(bao)石(shi)（Al2O3），云母（一種二氧化硅(gui)材料）和一些雙折射聚合(he)物。
（來源：網絡，版(ban)權歸原作(zuo)者，若有(you)侵權請聯系刪除）
