简介：Alow-thresholdRamaneffectinakilowattytterbium-dopednarrowbandfiberamplifiersystemisreported.TheRamanStokeslightat1120nmisachievedwiththetotaloutputpowerofonly~400W,indicatingthattheRamanthresholdofthiskilowattcodirectionalpumpedcontinuouswavefiberamplifierismuchlowerthanthepredictedvalueestimatedbytheclassicformula.Tofigureoutthemechanismofthisphenomenon,simulationsbasedonthegeneralstimulatedRamanscattering(SRS)modelareanalyzedindicatingthatthekeyfactoristhecouplingbetweenfour-wavemixing(FWM)andSRS.Thesimulationresultsareingoodagreementwithourexperiments.

简介：Alightpurplishredsapphireisheattreatedinanairtightcrucible.Thesamplechangeslittleincolorafterreceivingheattreatmentat1100°C,butturnstolightblueandblueafterbeingtreatedat1200°Cand1300°C,respectively.Beforeheating,theUV-VISabsorptionspectraofthesamplearedominatedbythe551nmbroadabsorptionbandcontributedbythed-electrontransition~4A_2→~4T_2ofCr~(3+).Afterheating,theUV-VISabsorptionspectraaredominatedbythe563nmbroadabsorptionbandcontributedbytheintervalencechargetransferofFe~(2+)-Ti~(4+).ThexrayphotoelectronspectroscopytestrevealsthattheFe~(2+)andTi~(4+)ioncontentsincreasewithincreasingtemperature.ThesapphirechangingfromlightpurplishredtoblueintheheatingprocessisowingtothefactthattheFe~(2+)andTi~(4+)contentsgrowandtheintervalencechargetransferofFe~(2+)-Ti~(4+)selectivelyabsorbsUV-VISlight.

简介：我们基于用与一个二进制树分类器相结合的高顺序的周期的cumulant察觉到压缩建议调整格式鉴定的一个方法。通过计算，pretreated乐队信号的第四顺序的周期的cumulant，它被获得由压缩了很与采样率察觉到不到Nyquist采样值，为分类的特征向量被提取。模拟与多重阶段移动调音和多重照振幅调整的不同调整格式在光协调纤维通讯系统被执行。结果显示这个方法能正确地并且高效地识别这些调整格式。同时，建议方法对激光阶段噪音和信号噪音感觉迟钝。

简介：Inthiswork,wereportabroadbandterahertzwavemodulatorbasedonatop-gategraphenefieldeffecttransistorwithpolyimideasthegatedielectriconaPETsubstrate.ThetransmissionoftheterahertzwaveismodulatedbycontrollingtheFermilevelofgrapheneviathepolyimideasthetop-gatedielectricmaterialinsteadofthetraditionaldielectricmaterials.Itisfoundthattheterahertzmodulatorcanachieveamodulationdepthof~20.9%withasmalloperatinggatevoltageof3.5Vandalowinsertionlossof2.1dB.