638 nm Wave Rotator Plate 90°
A cost-effective alternative to a polarization half wave plate, this product rotates the axis of polarization by a half wave or ninety degrees near the 638 nm wavelength. It is often used together with a PBS cube to combine two collimated beams at the same wavelength, allowing the power to be scaled without changing the beam’s optical properties.
Technical Data
Product Description
About the 638 nm Wave Rotator Plate 90°
- Cost-effective and easier to align alternative to traditional polarization half wave retarders (λ/2 wave plates)
- Can be used with a PBS cube for polarization combining
- V-AR coating allows transmission > 99% (typ.) around 638 nm
Half wave polarization rotators function by rotating the polarization axis of the linearly polarized beam of light by 90 degrees (lambda/2) near the design wavelength.
Polarization rotator plates are an excellent and far lower-cost alternative to a waveplate retarder. However, unlike traditional half waveplate retarders, the rotation of the polarization is independent of the angle of the optic about the z-axis (light propagation axis). This makes alignment much simpler compared to working with a half waveplate retarder.
Our half-wave polarization rotators are commonly used to combine beams in conjunction with a polarizing beamsplitter (PBS) cube designed for 638 nm. This is a cost-effective means to effectively double the power in an optical system without an increase in beam size or beam divergence resulting in a loss of etendue.
Although the design wavelength is 638 nm, this product may be used in the range of 620 – 660 nm with minimal loss of efficiency. This polarization rotator plate has dimensions of 10 x 10 mm with a nominal thickness of 5 mm, making it suitable for large or multiple beams adjoined by “knife edging”.
Opt Lasers also offers half-wave polarization rotator plates for wavelengths near 455 nm and 525 nm, as well as PBS cubes at the 455 nm, 525 nm, and 638 nm wavelengths.