thz waveplates 太赫兹波片 λ/2 plate gives phase delay π λ/4 plate gives phase delay π/2 a half-wave plate changes the polarization direction of linear polarized light a quarter-wave plate changes linearly polarized light to circular and vice versa thz waveplate for single operation wavelength retardation type, 1/2 λ, 1/4 λ operation wavelength 30-1000μm material thz grade crystal quartz orientation x-cut orientation tolerance ±10 min, arc standard dimensions 20×20mm, 50×50mm max. dimensions 60×60mm dimensions tolerance ±0.25mm thickness tolerance ±5.0μm clear aperture ≥90% parallelism 5 min, arc surface quality 60/40 scr/dig twd 1/2 λ@633nm