Detailed Product Description Narrow Band Beamsplitter Plate/ Half Mirror:SpecificationsMaterial BK7,B270,Float glass ate.Dimension ... Parallelism 1 arc minuteT/R 50/50±5%, for random polarization,T=(Ts+Tp)/2, R=(Rs+Rp)/2AOI45 deg.Back ... central wavelength coatings are available in prototype and production quantities.Beamsplitter also called half mirror,50/50 beamsplitters,Polarization beamsplitter