简介：WeinvestigatereactivefluorineatomspectroscopiccharacterizationinatmosphericpressureofHe/SF6plasmausingatomicemissionspectrometry.Asinputradiofrequency(RF)powerlevelsareraisedfrom140to220W,theemissionspectraof685.60(3p4D→3s4Ptransition)and739.87nm(3p4P→3s4Ptransition)increasesignificantly.Moreover,anoptimalvalueofSF6volumeconcentrationintheproductionoffluorineradicals,whichis0.8%isachieved.AdditionofcertainamountsofO2intoHe/SF6plasmaresultsinthepromotionofSF6dissociation.EmissionintensitiesoffluorineatomsshowthemaximumattheO2/SF6ratioof0.4.

简介：Wereportthefabricationofsubmicrometerpitsarray(SP-array)on6H-SiCsurfacebytheinterferenceoftwofemtosecondlaserbeams.FormationmechanismsandopticalabsorptionofSP-arrayarestudied.Therelativereflectivityandtransmissivityofwhitelightdecreaseto10%ofthevaluesofSiCcrystal,andtheopticalabsorptionisenhancedto97%.Therelativereflectivityandtransmissivityofincidentangleswithintherangeof20°-60°arekeptbelow25%.TheenhancementmechanismofopticalabsorptionoftheSP-arrayisalsodiscussed.