偏振PPT精選文檔

1、12第六章第六章 光的偏振和晶體光學(xué)基礎(chǔ)光的偏振和晶體光學(xué)基礎(chǔ)36.3 6.3 偏振光的產(chǎn)生、轉(zhuǎn)換和檢驗(yàn)偏振光的產(chǎn)生、轉(zhuǎn)換和檢驗(yàn)waveplatepolarizerpolarizer46.3.1 6.3.1 線偏振光的產(chǎn)生和檢驗(yàn)線偏振光的產(chǎn)生和檢驗(yàn)d51. 1.線偏振光的產(chǎn)生線偏振光的產(chǎn)生678（2 2）各種線偏器）各種線偏器9when the reflected beam makes aright angle with the transmitted beam,and the polarization is parallel, then no scattering can occur, du

2、e to the scattered dipole emission pattern.but our right-angle assumption implies that q qi + q qt = 90. so: thus, brewsters angle revisiteda complex trigonometric calcu-lation reveals that the reflectioncoefficient for parallel-polarizedlight goes to zero for brewstersangle incidence, tan(qi) = nt

3、/ nisin( )sin()iittnnqqsin( )sin(90) cos( )iititinnnqqqtan( )tiinnqnintqiqiqtqi +qt = 9010 折射式起偏器，玻璃堆折射式起偏器，玻璃堆11the pile-of-plates polarizerafter numerous brewster-angle transmissions, mainly the parallel polarization remains.unfortunately, only about 10% of the perpendicular polarizationis reflect

4、ed on each surface, so you need a big pile of plates!12dielectric polarizersa multi-layer coating can also act as a polarizer.glass13 二向色性起偏器二向色性起偏器, ,人造偏振片人造偏振片14polarizer transmitting vertical polarizationthis polarizer transmits horizontal polarization (of which there is very little).15wire grid

5、polarizerthe light can excite electrons to move along the wires, which thenemit light that cancels the input light. this cannot happen perpen-dicular to the wires. such polarizers work best in the ir.polaroid sheet polarizers use the same idea, but with long polymers.input light contains both polari

6、zations16wire grid polarizer in the visibleusing semiconductor fabrication techniques, a wire-grid polarizer was recently developed for the visible.the spacing is less than 1 micron.17 晶體線偏器晶體線偏器a .尼科尼科耳棱鏡耳棱鏡(nicol)18the nicol polarizer uses two identical prismsof calcite and tir off a layer of opti

7、cal cement. snells law separates the beams at the entrance. the perpendicular polarization then goes from high index (1.66) to low (1.55) and undergoes total internal reflection, while the parallel polarization is transmitted near brewsters angle.combine two prisms of calcite (with parallel optical

8、axes), glued together with canada balsam cement (n = 1.55).19尼科耳棱鏡的工作原理尼科耳棱鏡的工作原理 20b .b .格蘭格蘭(glan)(glan)棱鏡棱鏡 思考題：格蘭棱鏡的反射光石什么偏振態(tài)？思考題：格蘭棱鏡的反射光石什么偏振態(tài)？21格蘭棱鏡產(chǎn)生線偏振光的原理格蘭棱鏡產(chǎn)生線偏振光的原理 22real polarizersair-spaced polarizers23渥拉斯頓渥拉斯頓(wollaston)(wollaston)棱鏡棱鏡(a)(a)和羅雄和羅雄(rochon)(rochon)棱鏡棱鏡(b)(b) 24wollaston polarizing beam splitterthe ordinary and extraordinary rays have different refractive indicesand so diverge.the wollaston polarizing beam splitter uses two rotatedbirefringent prisms, but relies only on re