欢迎来到天天文库
浏览记录
ID:56303570
大小:1.20 MB
页数:17页
时间:2020-06-10
《信息获取技术和材料.ppt》由会员上传分享,免费在线阅读,更多相关内容在教育资源-天天文库。
1、光电探测器按光电转换方式,光电探测器可分为:光电导型、光生伏打型(势垒型)和热电偶型。光电转换中根据探测的光子波长分为:狭能隙半导体材料(红外)和宽能隙半导体材料(可见和紫外)。宽能隙材料以Si、Ge、和GaN、AlN等为主,狭能隙半导体材料主要为铅盐、碲镉汞、SbIn等。近期光电探测器最大的进展在两个方面:(1)用超晶格(量子阱)结构提高了量子效率、相应时间和集成度;(2)制成了探测器阵,可以用作成像探测。两者结合后最典型的例子为可以制成探测灵敏度极高的HgCdTe红外焦平面列阵(FPA),并成功地应用于红外遥感、成像等。Photodetector:convertlightint
2、oelectricitythroughthephotoelctriceffectRequirements:highsensitivity,fastresponse,lownoise,lowcost,andhighreliabilityRistheresponsivityofthephotodetector(A/W)thebandwidthofaphotodetectorisdeterminedbythespeedwithwhichitrespondstovariationsintheincidentopticalpower.TherisetimeTrisdefinedastheti
3、meoverwhichthecurrentbuildsupfrom10%to90%ofitsfinalvaluewhentheincidentopticalpowerischangedabruptly.tristhetransittimeandRCisthetimeconstantoftheequivalentRCcircuit.ThetransittimeisaddedtoRCbecauseittakessometimebeforethecarriersarecollectedaftertheirgenerationthroughabsorptionofphotons.Th
4、emaximumcollectedtimeisjustequaltothetimeanelectrontakestotraversetheabsorptionregion.Thereisatrade-offbetweenthebandwidthandtheresponsivity(speedversussensitivity)ofphotodetector.Often,theRCtimeconstantRClimitsthebandwidthbecauseofelectricalparasitics.Thesehigh-speedphotodetectorsshowflatres
5、ponseinbothamplitudeandphaseupto25GHzandareoptimizedforfrequency-domainapplications.Thehigh-sensitivityModel1414near-IRphotodetectorsuse25-µm-diameterback-illuminatedInGaAsSchottkyphotodiodeswithpeakresponsivitiesof0.6A/Wat1300nm.Theactivelayeristwiceasthickasinourultrahigh-speedModel101Xmodul
6、e,producinga50%greaterresponsivitybetween950nmand1650nm.Theconversiongainwitha50-Wloadis15V/W.25-GHzNear-IRPhotodetectorU2tXPDV2020R-VF-FPphotodetectorUltra-highspeedopticalpulsewaveformmeasurementisAchievedbyusingthesub-picosecondopticalpulsegenerationtechnologywithapassivelymode-lockedfiberl
7、aserandthenonlinearopticaltechnologywiththesum-frequency(SF)lightgeneration.
此文档下载收益归作者所有