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
| order no. | 1 piece in € | 2 piece in € | 3-5 piece in € |
|---|---|---|---|
| PLM 10 | 1328.- | 1214.- | 1122.- |
| PLM 15 | 1759.- | 1599.- | 1472.- |
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
| order no. | 1 piece in € | 2 piece in € | 3-5 piece in € |
|---|---|---|---|
| PUM 1.08 | 1569.- | 1433.- | 1324.- |
| PUM 1.10 | 2007.- | 1804.- | 1641.- |
| PUM 1.12 | 2467.- | 2208.- | 2002.- |
| PUM 1.15 | 3207.- | 2896.- | 2646.- |
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
| order no. | 1 piece in € | 2 piece in € | 3-5 piece in € |
|---|---|---|---|
| PUM 2.08 | 2447.- | 2200.- | 2003.- |
| PUM 2.10 | 3195.- | 2873.- | 2615.- |
| PUM 2.12 | 4047.- | 3639.- | 3312.- |
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.
