有源光子帶隙中量子點(diǎn)材料特性及全光開關(guān)的研究.pdf

1、華中科技大學(xué)碩士學(xué)位論文有源光子帶隙中量子點(diǎn)材料特性及全光開關(guān)的研究姓名：李慶申請(qǐng)學(xué)位級(jí)別：碩士專業(yè)：物理電子學(xué)指導(dǎo)教師：王濤20090517IIAbstractRecentlyastherapiddevelopmentoftheopticalcommunicationtechnologythedemfultrafastswitchesinthenodesbecomesincreasinglyurgent.Thenewalloptica

2、lswitcheswithdiversephysicalmechanismhaveattractedmemeinterestsbecauseofthefastresponseniceropticalacteristics.Therefeinthisarticleanallopticalpolarizationswitchwasinvestigatedwhichwasbasedontheonedimensionalphotoniccrys

3、tal(1DPC)madeofquantumdots(QDs)layersastheactiveregion.BecauseoftheevidentexcitoneffectoftheQDslayersintheroomtemperaturetheopticalstarkeffectwhichmeanspumpingtheexcitonbelowtheresonancethisswitchisabletoavoidthelimitati

4、onofcarrieraccumulationtoresponseinthepumppulsewidthtime.TheperiodsoftheQDslayersareBraggspacedwhichmeanstheBraggfrequencyisequaltotheexcitonfrequency.Atthistimethebgapofthe1DPCwillbeobvioussuppressedduetothesmallchangeo

5、ftheexcitonfrequencyrapidrecoveredafterthepumppulse.BycalculatingtheenergystructureofQDswediscussedtheopticalacteristicsofthesingleQDtheensembleofQDsestablishedthemodeloftheallopticalswitchbyusingthetransfermatrixapproac

6、hcomparedtheswitchingperfmancebetweentheQDsallopticalswitchtheBraggspacedquantumwells(BSQWs).FromthecalculationwecanconcludethatthisswitchneedslesspumpenergyhasahighercontrastratiobutalittledecreasedlossthanBSQWsintheroo

7、mtemperature.AtlastwepresenttheschemesfallopticalswitchingbasedonQDSOAwithPCbasedMachZehnderinterferometric.Itisexpectedthatourtheyconclusionsarehelpfulguidablefthedesignsexperimentsofthefuturepracticalopticalswitches.Ke