Specifications Aperture 1.0 ?1.0 mm2 to 4 ?4 mm2 Dimension tolerance ?0.05mm Wedge Angle tolerance ?0.1 degree Optical axis orientation ?0.5 degree Flatness lamda/4 @ 632.8 nm Surface Quality 20-10 AR-coating R< 0.2% Standard Sizes a) 1.25mm?.25mm?.25mm(top end) or 0.55mm(bottom end) b) 1.6mm?.6mm?.55mm Cutting Angle theta=90degree, fi=22.5 Wedge Angle 13degree or 15degree Coating Two apertures AR coated typically for ~1550 nm