The polarizer can pass through the linearly polarized light and block the orthogonal polarized light from the non polarized (or randomly polarized) light source. CRYLINK’s holographic linear grating polarizer works in the wavelength range of 2-30 µm (333-5000 cm-1), and is specially designed for this difficult to use spectral range. They were prepared using infrared transparent materials such as BaF2 , CaF2 , krs-5 (thallium bromide iodide) or ZnSe, and linear spaced grooves were prepared on the substrate by holographic method. The metal is then deposited on these grooves to form a wire grid. Because the light whose polarization direction is parallel to the wire grid will be absorbed and reflected, the polarization direction of the transmitted light is perpendicular to the wire grid. The direction of the grid is marked by a scribe.
The extinction ratio of these holographic linear grating polarizers ranges from 150:1 to 300:1, and they are pre installed in a double guard ring of 25 mm or 50 mm. The direction of the wire grid is parallel to the white marking on the mounting base. We suggest using this polarizer in pairs, which can provide smooth attenuation in a specific wavelength range and control the output polarization direction. If the grids of two polarizers are parallel, the extinction ratio can easily exceed 20000:1.
These polarizers are usually used to polarize the output of nonpolarized molecular lasers or to attenuate the polarized light source. They can also be used to adjust the output of the polarization beam splitter.
Parameter
Basic Parameters
| Material | BaF2 | CaF2 | KRS-5 | ZnSe |
| Extinction ratio | >150:1 (3µm) 300:1 (10µm) | >150:1 (3µm) 300:1 (8µm) | >150:1 (3µm) 300:1 (15µm) | >150:1 (3µm) 300:1 (10µm) |
| external diameter | 25 mm | 25 mm | 25 mm | 25 mm |
| Clear Aperture | Ø18.0 mm | Ø18.0 mm | Ø18.0 mm | Ø18.0 mm |
| Wire spacing | 2700 Grooves/mm (Nominal) | 2700 Grooves/mm (Nominal) | 2700 Grooves/mm (Nominal) | 2700 Grooves/mm (Nominal) |
| Substrate thickness | 2.0 mm ± 0.5 mm | 2.0 mm ± 0.5 mm | 2.0 mm ± 0.5 mm | 2.0 mm ± 0.5 mm |
| Parallelism | ≤3 arcmin | ≤3 arcmin | ≤3 arcmin | ≤3 arcmin |
| Transmitted wavefront distortion | λ/20 @ 10.6 μm | λ/20 @ 10.6 μm | λ/10 @ 10.6 μm | λ/20 @ 10.6 μm |
| Ring thickness | 5.0 mm ± 0.2 mm | 5.0 mm ± 0.2 mm | 5.0 mm ± 0.2 mm | 5.0 mm ± 0.2 mm |
| Ring diameter tolerance | +0.0/-0.2 mm | +0.0/-0.2 mm | +0.0/-0.2 mm | +0.0/-0.2 mm |
| external diameter | 50 mm |
| Clear Aperture | Ø34.0 mm |
| Wire spacing | 2700 Grooves/mm (Nominal) |
| Substrate thickness | 3.0 mm ± 0.5 mm |
| Parallelism | ≤3 arcmin |
| Transmitted wavefront distortion | λ/10 @ 10.6 μm |
| Ring thickness | 5.0 mm ± 0.2 mm |
| Ring diameter tolerance | +0.0/-0.2 mm |
Application
- Polarization initiation of nonpolarized molecular lasers
- Attenuation of polarized light source
- Adjusting the output of polarization beam splitter
Feature
- Polarization wavelength: 2 – 30 µm
- Extinction ratio: 150:1 to 300:1 (see specification label)
- Two sizes are available: Ø 25 mm and Ø 50 mm
- It is installed in double protection ring with grid direction indication
Spectrogram
