简介:Aneworganic-inorganichybridmaterial,whichshowsphoto-inducedreductionofrefractiveindexaswellasvolumecontraction,ispreparedusingasol-gelmethod.ThismaterialiscoatedonaSisubstratebyspin-coatingtomanufacturefilm.Afterirradiatedbyultraviolet(UV)lightwithadeuteriumlampfor5h,thethicknessoffilmdecreaseslargelyby55%,andtherefractiveindexoffilmchangesfrom1.484to1.445at550nm.Thefilm'sopticalthicknessexhibitsanexponentialchangewiththeincreasingirradiationtime.Futhermore.thephoto-patternningoftheorganic-inorganichybridfilmwithoutanyfurtherprocess(wetetchingandthermalcuring)isperformedutilizingthevolumecontractiononUV-lightirradiation.Thisfilmhaspotentialapplicationsforfabricationofpatternedfilterarrayandapodizingfilterbydirectlightwriting,andalsodemonstratesgoodtemperaturestabilityandimmunitytovisiblelightexposure.
简介:HighorderBraggscattering(M=2andM=3)operationsofthedistributedfeedbackdyedopedsol-gelsilicalasersareachievedusingthesecondharmonicoutputofaNd:YAGlaserasthepump.Laserlinewidthoflessthan0.06nmandconversionefficiencyof0.7%forM=3and11%forM=2aremeasured.Wavelengthtuningofabout15nmaroundtheemissioncenterhasbeenrealizedbyvaryingtheintersectionangle.