Newport's true zero-order wave plates consist of a birefringent polymer film cemented between two high-precision BK 7 windows, each with a high efficiency, broadband antireflection coating. This construction ensures excellent transmitted wavefront quality, while minimizing beam deviation and surface reflection losses. The assembly is mounted in a black anodized aluminum housing for protection and ease of mounting, with the wave plate fast axis marked for alignment reference.Polymer wave plates offer benefits over quartz wave plates such as better angular acceptance and less sensitivity to wavelength change. Polymer wave plates have excellent angular field of view. Retardation changes by less than 1% over a ±12° incidence angle. The polymer material has very low birefringence that is nearly constant with wavelength. The retardance δ at a new wavelength λ that is different from the center wavelength λc is given by:δ = δc(λc/λ) where δc is the retardance at λc. In addition, large aperture wave plates are less costly to fabricate in polymer than they are in quartz.These wave plates are available in λ/4 or λ/2 retardation at ten common laser wavelengths. Our standard 12.7, 25.4, and 50.8 mm outer diameters are convenient for mounting into Newport rotary mounts.
To order, substitute the desired standard wavelength (in nm) for "λ" in the part number. Wavelengths include: 488, 514.5, 532, 632.8, 670, 780, 830, 1064, 1300 and 1550 nm. For example, model 20RP34-532 is a 50.8-mm diameter, λ/4 retardation, 532 nm wavelength wave plate.