有機(jī)非線性光學(xué)材料的從頭算研究.pdf

1、武漢科技大學(xué)碩士學(xué)位論文有機(jī)非線性光學(xué)材料的從頭算研究姓名：杜文風(fēng)申請學(xué)位級別：碩士專業(yè)：材料學(xué)指導(dǎo)教師：汪厚植羅時軍20080510AbstractNonlinearopticsisasubjecttostudytheinteractionofintenselaserwithmatteranditisarapidlydevelopedsubjectafterthebirthofthelaserAstheimportantembranc

2、hmentofthefieldofmodernoptics，nonlinearopticsiSattractingpeople’SextensiveattentionIthasbecomeailimportantprojecttofindnewnonlinearopticalmaterialswithstrongnonlinearopticalpropertiesandquickresponseduetotheirattractivea

3、pplications，forinstance，inmodemlasertechnologyopticalcommunication，datastorage，opticalinformationprocessingandotherfieldsMuchemphasishasbeenputoutfororganicnonlinearopticalmaterialsbecausetheyhavemanyadvantages，suchaslar

4、genonlinearopticalcoeffieient，wideresponsewaveband，goodflexibilityhighopticaldamagethreshold，lowcost，andeasycombinationandmodificationThethesishasstudiedthelinearandnonlinearopticalpropertiesoforganicmaterials；weevaluate

5、thedielectricfunctionandthesecondharmonicgenerationresponsecoefficientOVerawidefrequencyrangeandtherelationshipbetweentheopticalpropertiesandtheelectronicstructureThemaincontentsandresultsarerepresentedasfollowsCrystalli

6、neureaisamongthefirstorganicmaterialsfoundtohaveanapplicationinnonlinearoptics，alsoitisamongthesimplestorganiccrystalswhichhaveasecondharmonicresponseSoitsverysignificanttostudythemicroscopicmechanismofthenonlinearoptica

7、lpropertiesofureacrystalAsystematicabinitiostudyoftheelectronicstructureandtheopticalpropertiesofureacrystalispresentedOurresultsareingoodagreementwiththeexperimentsThevirtualelectronandvirtualholeprocesshasalsobeenperfo

8、rmedWefindthatthevirtualholeprocesshasnearlynocontributiontononlinearopticalresponseoftheureacrystalNMBAisapromisingcandidatefornonlinearopticalapplications，oneofitsnonlinearopticalcoefficientsisverylargeAndthemoleculars

9、tructureofNMBAis“D一7c—A”towhichmanyresearcherespayaattentionrecentlyWereportfofthefirsttimetheelectronicandopticalpropertiesofNMBAobtainedbythefullpotentialprojectedaugmentedwavemethodThestudyoftheelectronicstructureshow

10、sthatthebandstructureofNMBA，whichisflatandnotseriouslydispersiveistypicalofaninsulatingsystemThecontributionof2pstatesofNandOinnitrototheboRomofconductionbandsisverylarge，thenitroisthemaincontributionresourceofthelineara

11、ndnonlinearpropertiesFromtheelectrondeformationdensitymapsofthemolecule，wecallseethatNMBApossessestwoprimaryintermolecularhydrogenbondandthechargetransferappearsfromtheelectrondonatinggroupCH3totheelectronwithdrawgroupN0

12、2，twophenylactasagoodelectronicmediumthroughwhichchargeCanbetransferred，therebytheSHGresponseisenhancedTheopticalpropertiesofNMBAshowaconsidaableanisotropyThemagnitudeofthepeaksof《@)ismuchgreaterthanthatofthepeaksof占：，細(xì))

13、and《(緲)，and石listhedominantThestudyofthecontributionsofdifferenttransitionstotheSHGcoefficientsshowsthatthevirtualelectronsprocessisdominantandvirtualholeprocesscannotbeneglectedThecontributiontothelargecomponentzPfromvir