Beam Displacer
Specifications:
Material: YVO4
Dimension Tolerance: ± 0.05mm
Optical Axis Orientation: ± 0.5°
Parallelism: < 15 arc sec
Perpendicularity: < 10 arc min
Flatness: λ /4 @ 633nm
Surface Quality: 60-40
AR Coating: R < 25% @ 1550 ± 40nm or other wavelength
Based on the birefringence performance of YVO4, a Beam Displacer can divide a beam into o-rays and e-rays. When a natural beam transmits through a birefringent crystal, the beam divides into two rays. One ray transmits through the crystal in a strait path, this ray is called the ordinary ray (o-ray). the other ray is transmitted through the crystal, but changes its direction. This ray is called the extraordinary ray (e-ray). The angle between the o-ray and the e-ray is called the walk off angle α. It is given by:
α = tg-1( no2/ne2 * tgθ )-θ
θ is the angle between the light beam and the optical axis
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Part No.
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Material
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Size
|
d
|
θ
|
φ
|
Coating
|
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BDP6507
|
YVO4
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2.6×2.6×7.0mm
|
0.70mm
|
45°
|
0°
|
AR/AR @ 1550 ± 40nm
|
|
BDP6510
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YVO4
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2.6×2.6x10mm
|
1.00mm
|
45°
|
0°
|
AR/AR @ 1550 ± 40nm
|
|
BDP6512
|
YVO4
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2.6×2.6x12mm
|
1.20mm
|
45°
|
0°
|
AR/AR @ 1550 ± 40nm
|
|
BDP6515
|
YVO4
|
2.6×2.6x15mm
|
1.50mm
|
45°
|
0°
|
AR/AR @ 1550 ± 40nm
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(d is the distance between o-ray and e-ray)