指标如下：
Item Description: Compound Zero Order Waveplates
Clear Aperture (mm): N/A
Transmitted Wavefront Distortion: <λ/10 p-v at 633nm
Surface Quality: 10-5 scratch-dig per MIL-PRF-13830b
Ring Mount Outer Diameter (mm): 25.4
Retarder Construction: Compound Zero Order Waveplates
Retardation: λ/2
Mount Type: Air-Spaced Ring Mounted
Housing Thickness (mm): 6.35
Housing Aperture (mm): 15
Diameter (mm): 20
Wavelength (nm): 1064