Waveplate Overview

Introduction of Waveplate

Waveplate is an optic in which the polished faces contain the optical axis. All light incidents normal to the surface are composed of components polarized parallel and perpendicular to the axis. In such a device, light polarized parallel to the axis will propagate slower than light polarized perpendicular to the axis. As the light propagates through the optic, the phase shift between the two components with various thickness. The phase shift is called retardance. The most popular retarders are quarter and half wave. with an appropriate choice of thickness, any degree of retardance may be achieved at any wavelength for which quartz is transparent. However, the minimum thickness necessary to achieve a mechanically strong part corresponds to several full waves of retardance.

Photonchina’s waveplate can transmit light and modify its polarization state without attenuating, deviating, or displacing the beam.It is ideal for applications requiring high damage thresholds and retardation stability over temperature change, such as for use with lasers or infrared light sources.

Production

Photonchina’s waveplates fabrication starts from quartz materials cutting with their axes oriented within a few arcminutes before being polished to a laser-quality finish, arcsecond parallelism, and <λ/10 wavefront. Their thickness tolerance is a only small fraction of a micron. To verify retardation tolerances, specially-trained optical technicians use purpose-built test gear. After anti-reflective coating, zero order and achromatic waveplates are matched in pairs and accurately aligned to each other within their cell mounts.

Waveplate retardation catagory:

Photonchina’s waveplates include octadic waveplate (1/8), quarter waveplates(1/4), half wave plates(1/2) and full waveplate.

Both circular aperture and quadratic aperture are available.

Half Waveplate

A half waveplate rotates linearly polarized light to any desired orientation. The rotation angle is twice the angle between the incident polarized light and optical axis.


half waveplate

 
Quarter Waveplate

When linearly polarized light is input at 45deg to the axis of a quarter waveplate , the output is circularly polarized similarly, input circularly polarized light is transformed into linearly polarized light.

quarter waveplate

Photonchina provides standard waveplate wavelengths (nm) listed as below:The thickness of the quarter waveplate is such that the phase difference is 1/4 wavelength ( λ /4, Zero order) or certain multiple of 1/4-wavelength [(2n+1)λ /4, multiple order].

355532632.880885098010641310148015501590

Note: Other wavelengths within the ranger of 200-2300nm are also available.

 

Standard Specifications:
Material: Crystal Quartz
Dimension tolerance: +0.0, -0.1mm
Wavefront distortion: < l /8@632.8
Retardation tolerance: < l /500
Wavelength range: 240-2100 nm
Parallelism: <1 arc second
Surface quality: 20/10 scratches and dig
Clear aperture: >90%
AR coating: R<0.2% at central wavelength
Standard Wave: quarter-wave ( l /4), half-wave ( l /2)

Waveplate types

Waveplate Type Structure Features More Details
Low order/Multi order
Low Temperature Bandwidth
Low Wavelength Bandwidth
High damage threshold
Low cost

low order waveplate

Zero order
Cemented
Cemented by glue
Better Temperature Bandwidth
Wide Wavelength Bandwidth
Moderate damage threshold

waveplate zero cemented

Optical Contacted
No glue
Better Temperature Bandwidth
Wide Wavelength Bandwidth
Better damage threshold
Good wavefront and parallelism

waveplate zero cemented

Air Spaced
No glue, Mounted
Better Temperature Bandwidth
Wide Wavelength Bandwidth
High damage threshold

waveplate air spaced

True zero order

Cemented

Cemented by glue
Better Temperature Bandwidth
Wide Wavelength Bandwidth
Moderate damage threshold
Excellent retardation performance

True zero order waveplate

Single Plate
Single plate
Better Temperature Bandwidth
Wide Wavelength Bandwidth
High damage threshold
 
Waveplate true zero single
 
Dual Wavelength

Provide Specific Retardance At Two Different Wavelengths

low order waveplate

Achromatic
Better Temperature Bandwidth
Very broad Wavelength Bandwidth
Cemented and air spaced available

waveplate achromatic

How to choose a waveplate?

01. Phase Retardation

First, make sure of the phase retardation, full, half or quarter? 

Or special phase like octadic?

02. Size and Wavelength

Secondly, specify the size and wavelength.

03.The Type of Waveplate

Finally, the type of waveplate should be determined. If you want the waveplate to be used in a wide temperature range and a broad wavelength range, you should choose zero order or true zero order waveplate. For the zero order waveplate, the cemented or glued zero order is relatively cheap, and the optically contacted zero order and air spaced zero order damage thresholds are high. The parallelism and wavefront distortion of true zero order waveplate is the best, which is used in particularly important systems. If you have no requirements for wavelength bandwidth and temperature range, multiorder (low order) waveplate will be a cost-effective choice.

If you need a wavelength bandwidth of more than 100nm, you should choose achromatic waveplate. Regarding dual wavelength waveplate, it is particularly useful when used in conjunction with other polarization sensitive components to separate coaxial laser beams of different wavelength