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Laser Retarders(Waveplates) / Archromatic Waveplates

Lasers Optics

Waveplates

Laser Retarders (Waveplates)

We fabricate these from selected natural and synthetic crystalline quartz, and other crystals depending upon wavelegth.
All of our quartz Retarders are multi-layer antireflection coated on both sides so that transmittance exceeds 99% at the design wavelength. Precision of retardation is guaranteed to be within ¼% of design value. Transmitted wave-front is better than 1/10-wave across the full aperture. We calibrate every Retarder which is shipped out. We will furnish upon request, and at no additional charge, the calibrated value of any plate.
Aperture is 15 mm 1◣cell with scribed line indicating slow axis. Surface quality 10/5 or better, flatness better than 1/20 wave, parallel better than 2 seconds.

This is the single plate Retarder, and is no more nor less accurate than the zero order type under ordinary laboratory conditions. They will display more sensitivity to temperature change than the zero-order type. These Retardation Plates are precision polished to achieve the desired retardation at the desired wave-length. Aperture is 15mm.
The high dispersion of refraction index at shorter wavelengths narrows both angular aperture and bandwidth. Thus, we limit our multiple-order Retarders to 400 nm and longer wavelengths. For UV excimer lasers, we recommend our more tolerant zero-order Retarders Both sides are AR coated.
We manufacture Retarders from 3.6伊m to 7.0伊m on a custom basis in MgF昏crystal. Please inquire.
Change in phase retardation (汁白) relates to bandwidth, field of view and temperature change, using a 1 mm thick plate. Temperature stability describes the change in phase retardation per c of temperature change.

Material

Retardance

Parallel

Crystal quartz

±½%

1 second

Quarter-wave	Half-wave

*Value assumes a tolerable phase retardation error of 1% MANY MORE WAVELENGTHS IN STOCK. IF NOT, WE'LL MAKE IT.	*Value assumes a tolerable phase retardation error of 1% MANY MORE WAVELENGTHS IN STOCK. IF NOT, WE'LL MAKE IT.

OFR manufactures and stocks ½-wave and ¼-wave Retarders in common laser wavelengths, cemented between protective glass cover plates. We do not AR coat mica Retarders, as internal transmittance is ~85%. However, mica Retarders are very high quality plates, with uniform retar-dance across the aperture, and wave-front distortion ˉ¼-wave. Because of the natural absorptance of mica, insertion losses become quite high with increasing wavelength(the plate becomes thicker).Thus, for practicality, we do not recommend mica retarders beyond ~850nm.
Mica Retarders are guaranteed to be accurate within 1% of peak value.

Material

Retardance

Parallel

Mica between glass

±1%

2 minutes

*Value assumes a tolerable phase retardation error of 1%

These are air-spaced, double plate Retarders. All surfaces are AR coated. These are no more nor less accurate than the multiple-order type under ordinary laboratory conditions. However these have wider bandwidth and less sensitivity to temperature change than the multiple-order type. These Retardation Plates are within the ※zeroth§ order of retardance, that is between(0伙-1伙).

Material

Retardance

Parallel

Crystal quartz

±½%

2 second

Quarter-wave	Half-wave

*Value assumes a tolerable phase retardation error of 1% MANY MORE WAVELENGTHS IN STOCK. IF NOT, WE'LL MAKE IT.	*Value assumes a tolerable phase retardation error of 1% MANY MORE WAVELENGTHS IN STOCK. IF NOT, WE'LL MAKE IT.

A ½-wave retarder will rotate the plane of polarization by an amount that is twice the angle between the retarder axis (the white scribed line on the Cell) and the polarization plane.
This Retarder is a combination of birefringent crystal plates, resulting in broadband phase retardation accurate within 1% across the designated spectrum.
With broadband AR coatings, these Retarders transmit ˇ98%. Mounted in standard Cell.
Aperture is 15 mm

*Value assumes a tolerable phase retardation error of 1%

Material

Retardance

Parallel

Crystal quartz + MgF2

±½%

2 seconds

Lasers Optics

Waveplates

Archromatic Waveplates

Achromatic waveplates retard accurately over a range of wavelengths with virtually no image offset. They take up about the same amount of space as non-achromatic wave-plates. Exact retardation tolerances are a function of wavelength. The useful spectral range of achromatic optics is the same as crystal quartz, 170-2700nm. KLC zero-order achromatic waveplates are made of plates of crystal quartz and magnesium fluoride. KLC also manufactures super-achromatic waveplates. Super-achromatic plates have a lower retardation error over a wider wavelength range than achromatic plates, but are available only on special order. Achromatic Fresnel rhomb retarders are a less costly alternative but are bulkier than achromatic waveplates. Material Properties. Magnesium fluoride is a colorless, crystalline compound, with slight birefringence.It is not optically active. Crystal quartz is optically active and is a highly transparent, slightly birefringentmaterial.


	Achromatic waveplates may be supplied unmounted, or mounted in a non-reflective black cell mount for handing ease and added durability. They may be assembled cemented or optically contacted . Two kinds of cement are used, for different applications. For waveplates designed to transmit wavelengths of light shorter than 300nm, the cement used will transmit 80% at 220nm and less as wavelengths get shorter. For waveplates transmitting wavelengths of light longer than 300nm, the cement used will transmit 80% at 280nm and less for shorter wavelengths. For shorter wave-length ranges, optically contacted achromatic waveplates are recommended. Optional anti-reflection coatings include broad-band single layer(BB) and high efficiency multilayer(HEAR). Uncoated waveplates are assembled with the magnesium fluoride plates on the outside; coated waveplates are custom made, and normally have a 22mm clear aperture diameter.

Fresnel Rhombs

The most achromatic of all Retarders are the Fresnel Rhombs. We manufacture both 1/4-wave and 1/2-wave models for the ultraviolet and the visible-near IR. Surface quality 10/5 or better, flatness better than 1/10 wave, parallel better than 10 seconds.
MOUNTING CELLS are provided with the Fresnel Rhombs. Both cells have 1/4-20 holes for standard bench post mounting.
The 1/2-wave Retarders Mounting Cell also mounts into 2◥dia. mirror mount


RF - 1/4	*Value assumes a tolerable phase retardation error of 1%

RF - 1/2	1/4 - Wave	1/2 - Wave