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Photonics West
27.01.- 01.02.2018
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Photonics West in San Francisco
Booth 4529


Rochon Polarizers

Rochon Polarizers


The Rochon polarizers consist of two identically shaped prisms made from birefringent magnesium fluoride (MgF2). The crystal axis is parallel to the propagation direction in one prism and orthogonal to it in the other one. Therefore, the extraordinary beam gets refracted on the passage while the ordinary beam passes without deviation at all wavelengths. For this reason Rochon polarizers are particularly suited in application requiring a rotating polarizer. The polarization of the ordinary beam is parallel to the plane of splitting.

We provide the prisms by default with a cylindrical holder and without antireflection coating. The holders are entirely free of cement which makes them suited for vacuum conditions.p>

We offer Rochon polarizers with three different splitting angles. The version with a splitting angle of 0,5° is assembled with air gap between the prisms. This version suited for high laser powers in the UV as well as for application involving increased thermal loads. The inner surfaces are cut at Brewster angle which minimizes reflective losses of the ordinary beam on these surfaces.

For the versions with splitting angles of 2,5° and 4° the required cut angles are larger and would imply total internal reflection on an air gap. Therefore, the prisms are joined by cementless optical contact.

Optical specifications

Divergenzwinkel 0,5° 2,5° 4,0°
material MgF2 VUV quality MgF2 VUV quality MgF2 VUV quality
spectral range 150-6000 nm 150-6000 nm 150-6000 nm
extinction ratio 10-5 10-5 10-5
wavefront distortion <λ/5 <λ/5 <λ/5
prismatic deviation <3’ <3’ <3’
cut angle 34,0° 73,5° 80,3°
connection of the prisms air gap optical contact (no cement) optical contact (no cement)

Optical specifications

format
10 mm 15 mm
Article-No.:
PLM 10 PLM 15
free aperture [mm] 9,5 14,5
Length [mm] 11 13
mount diameter [mm] 25 25
mount length [mm] 16 20

Prices

Art.-No. 1 pieces in € 2-5 pieces in € 6-10 pieces in €
PLM 10 1290,- 1179,- 1051,-
PLM 15 1717,- 1561,- 1384,-

Optical specifications

format
8 mm 10 mm 12 mm 15 mm
Article-No.:
PUM 1.08 PUM 1.10 PUM 1.12 PUM 1.15
free aperture [mm] 8 10 12 15
Length [mm] 29 36 42 52
mount diameter [mm] 25 25 25 25
mount length [mm] 38 45 53 57

Prices

Art.-No. 1 pieces in € 2-5 pieces in € 6-10 pieces in €
PUM 1.08 1517,- 1385,- 1234,-
PUM 1.10 1954,- 1756,- 1530,-
PUM 1.12 2414,- 2161,- 1872,-
PUM 1.15 3158,- 2851,- 2500,-

Optical specifications

format
8 mm 10 mm 12 mm
Article-No.:
PUM 2.08 PUM 2.10 PUM 2.12
free aperture [mm] 8 10 12
Length [mm] 50 62 74
mount diameter [mm] 25 25 25
mount length [mm] 60 72 84

Prices

Art.-No. 1 pieces in € 2-5 pieces in € 6-10 pieces in €
PUM 2.08 2383,- 2143,- 1869,-
PUM 2.10 3127,- 2812,- 2452,-
PUM 2.12 3987,- 3585,- 3125,-

n the prism having the axis direction parallel to the propagation direction (left side in the sketch) the material ideally does not show birefringence. However, small deviations of the propagation direction (e.g. due to tolerances of integration or divergent light) cause the material to become birefringent. The resulting change of polarization can act as an apparent depolarization which limits the observed extinction ratio. The other half of the prism having the crystal axis perpendicular to the propagation direction does not suffer from this effect. This side is always set towards the engraved side of the holder.

If used as a polarizer (i.e. to generate polarized light after the prism) the light should enter from the non-engraved side of the holder. If used a analyzer (i.e. to analyze the polarization state of the incident light) the engraved side should be oriented towards the incident light. Thus, when used in a pair as polarizer and analyzer the engravings of the holders must face each other.