W***eplates(retardationplatesorphaseshifters)aremadefrommaterialswhichexhibitbirefringence.Thevelocitesoftheextraordinaryandordinaryraysthroughthebirefringentmaterialvariesinverselywiththeirrefractiveindices.Thisdifferenceinvelocitiesgivesrisetoaphasedifferencewhenthetwobeamsrecombine.Inthecaseofanincidentlinearlypolarizedbeamthisisgivenbyδ=2πd(ne-no)/λ,whereαisphasedifference;disthinknessofw***eplate;ne,noarerefrectiveindicesofextraordinaryandordinaryraysrespectively;λisw***elength.Atanyspecificw***elengththephasedifferenceisgovernedbythethinknessoftheretarderStandardW***eplatesIncludingfull-w***e(λ),half-w***e(λ/2),quarter-w***e(λ/4)andoctadic-w***e(λ/8)platesarewidelyusedinsynthesisandanalysisoflightinvariousstatesofpolarization.W***eplates(retardationplatesorphaseshifters)aremadefrommaterialswhichexhibitbirefringence.Thevelocitesoftheextraordinaryandordinaryraysthroughthebirefringentmaterialvariesinverselywiththeirrefractiveindices.Specificationofourw***eplateasfollow:*DimensionTolerance:+/-0.20mmto+0.01/-0.01mm*ThicknessTolerance:+/-0.20mmto+/-0.005mm*SurfaceQuality:80-50to10-5*Flatness:at633nmlambda--lambda/20per25mm*ClearAperture:80%--100%*Paralleli***(arcmin):3min--3sec*Crystalsdirectionalprecision:5minto30sec*Bevel:0.3+/-0.20mm*45degree*NoBevel*CoatingR<0.2%*Otherw***elengthswithintherangeof200-2300nmarealso***ailableuponrequest.)