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| Information |
| Name： | Savart Plate |
| Categories： | Optics >> Polarizer |
| Model： | SPL |
| Specifications： | |
| Brand： | SPL |
| Product Code： | |
| Color： | |
| Price： | |
| Clicks： | 141 |
| Date： | 2010-04-13 05:04:49 |
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The Savart plate comprises two beam displace plates with their optic axes at 45° to the surface normal, rotated 90° with respect to each other. An incident beam propagating through Plate 1 is resolved into ordinary and extraordinary beams which are displaced from each other in the 1st principal plane. Upon entering Plate 2, the ordinary beam becomes an extraordinary beam, and vice-versa. Splitting again takes place in the 2nd principal plane, which is orthogonal to the 1st. The result is two emerging beams displaced along a diagonal. The displacement is root 2 times that of each plate. The optical path difference between the 2 beams is zero for normal incidence.
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Operation
When placed between parallel or crossed polarizers, a collimated input beam produces a set of parallel fringes. The Savart plate can be used to detect very weakly polarized light in the presence of mainly unpolarized light - typically starlight. The intensity of the interference bands is indicative of the degree of polarization.
When used with a diffraction grating, the plate functions as an achromatic retardation plate for the diffracted orders. Savart plates can be manufactured in both a-BBO and calcite, and are cemented together to transmit from UV to IR wide spectral range.
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Beam Displacement
The beam displacement produced by the Savart plate is 0·075 times the total thickness of both plates for calcite at 500nm, and 0·074 times the total thickness for a-BBO at 300nm. For any required displacement, this factor can be used to calculate the corresponding total thickness. When ordering a Savart plate, specify the aperture and total thickness. For example, a combined thickness of 10mm, will produce a displacement (shear) of 0.75mm (750μm). Note that the spectral dispersion of the displacement varies in the same fashion as that of beam displacers (q.v.)
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Mounts
Savart plates can be supplied unmounted as free components or mounted as shown. The mount comprises a black anodised aluminium ring with silicone rubber shock absorbing material between the ring and the plate. To specify mounted displacers, simply add suffix:
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Specifications
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Part No
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Material
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Aperture (mm)
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Spectral Range (nm)
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Peak Trans. (%)
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Flatness
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Savart Plates – a-BBO
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SPL1310
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a-BBO
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10
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220-3000
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90
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lambda/4
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SPL1315
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a-BBO
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15
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220-3000
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90
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lambda/4
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SPL1320
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a-BBO
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20
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220-3000
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90
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lambda/4
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SPL1325
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a-BBO
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25
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220-3000
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90
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lambda/4
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SPL1330
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a-BBO
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30
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220-3000
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90
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lambda/4
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Savart Plates - Calcite
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SPL1410
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Calcite
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10
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350-2500
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90
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lambda/4
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SPL1415
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Calcite
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15
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350-2500
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90
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lambda/4
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SPL1420
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Calcite
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20
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350-2500
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90
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lambda/4
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SPL1425
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Calcite
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25
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350-2500
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90
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lambda/4
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SPL1430
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Calcite
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30
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350-2500
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90
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lambda/4
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Customer can define the thickness follow our P/N like SPL1320-5, means 5mm total thickness |
