實(shí)驗(yàn)三-水平配向樣品之光電量測(cè)

實(shí)驗(yàn)三-水平配向樣品之光電量測(cè)TA:Tinda.InstituteofElectronic-opticalscienceandengineering大綱一、目的二、儀器設(shè)備及材料三、理論原理四、實(shí)驗(yàn)步驟InstituteofElectronic-opticalscienceandengineering一、目的學(xué)習(xí)水平配向樣品於電壓控制下穿透度之量測(cè)，藉以瞭解液晶轉(zhuǎn)向之物理與光電特性變化。InstituteofElectronic-opticalscienceandengineering二、儀器設(shè)備及材料儀器設(shè)備：自動(dòng)電壓量測(cè)系統(tǒng)(波形產(chǎn)生器、數(shù)位電表、電壓放大器、GPIB介面卡、PC、光偵測(cè)器)、偏振片、氦氖雷射、光衰減片(NDF)、反射鏡、偏光顯微鏡、配向機(jī)、烤箱、ITO玻璃清潔設(shè)備、玻璃切割機(jī)使用材料：良好水平配向液晶樣品一片(由實(shí)驗(yàn)二取得)。InstituteofElectronic-opticalscienceandengineeringLinearPolarization(a)若Δ之整數(shù)倍時(shí),(b)若Δ之奇數(shù)倍時(shí),任一沿z方向前進(jìn)之線(xiàn)偏振光,其電場(chǎng)E(z,t)之偏振方向必平行於x-y平面,若Δ為相位差k=2/;=2/T三、理論原理InstituteofElectronic-opticalscienceandengineeringCircularPolarization(a)若Δ(-/2)m之整數(shù)倍時(shí),(b)若Δ(/2)m之奇數(shù)倍時(shí),;Δ為相位差振幅相等為InstituteofElectronic-opticalscienceandengineering外加電場(chǎng)對(duì)nematic相的影響

對(duì)一nematic相液晶外加一電場(chǎng)E，此時(shí)電場(chǎng)對(duì)系統(tǒng)之能量貢獻(xiàn)可寫(xiě)為InstituteofElectronic-opticalscienceandengineeringU1U2VoffVonIndexEllipsoid:x2/no2+y2/no2+z2/ne2=1(Foranuniaxialcrystal:nx=ny=no,nz=ne)

=2nd/=π/245oEzExkdITOGlassesITOGlassesExEykBirefringenceofLC

z(opticalaxis)yx=x’noO

nenoInclinedplane

z’y’neff()none/(no2sin2+ne2cos2)1/2InstituteofElectronic-opticalscienceandengineeringInstituteofElectronic-opticalscienceandengineeringAnisotropicO

nenonP-waves-waveP-waves-waveIsotropicdABAB△Phase=kxdExperimentalapparatusformeasuringbirefringenceandphaseretardationofaparallelalignedLCcell.dITOGlassesInstituteofElectronic-opticalscienceandengineeringE–wavephase:O–wavephase:Phaseretardation:NormalizedlighttransmittanceT.x:anglebetweenthepolarizer&analyzer.β:anglebetweenthepolarizer&frontLCdirectors.InstituteofElectronic-opticalscienceandengineeringO

nenoDisplay:λ/2plateInstituteofElectronic-opticalscienceandengineering四、實(shí)驗(yàn)步驟(1)先瞭解如圖(1)之自動(dòng)電壓量測(cè)系統(tǒng)方塊圖之工作原理。InstituteofElectronic-opticalscienceandengineering(2)如圖(2)之實(shí)驗(yàn)裝置架設(shè)圖所示，液晶樣品前後各放置一片起偏鏡P(設(shè)穿透軸與x軸夾+45度)與檢偏鏡A，氦氖雷射偵測(cè)光經(jīng)過(guò)兩偏振片與水平配向液晶樣品(液晶導(dǎo)軸沿x方向)後，分別量測(cè)不同電壓值下兩種狀況時(shí)之穿透光強(qiáng)度T平行與T垂直。InstituteofElectronic-opticalscienceandengineeri