Thorlabs’ Wire Grid Polarizing Beamsplitter Cube consists of an array of parallel metallic wires sandwiched between two N-BK7 prisms. Wire grid polarizers transmit radiation with an electric field vector perpendicular to the wire and reflect radiation with the electric field vector parallel to the wire. This cube separates the s- and p-polarized components by reflecting the s-polarized component at the wire grid, while allowing the p-polarized component to pass. Due to surface reflections, the reflected beam contains both polarizations.
This type of beamsplitter cube has a larger Angle of Incidence (AOI) than traditional broadband polarizing beamsplitter cubes. For the highest polarization extinction ratio, use the transmitted beam, which offers an extinction ratio of Tp:Ts > 1 000:1 for an AOI from 0° to 5°. For higher AOI (5° to 25°), this cube can maintain an extinction ratio of Tp:Ts > 100:1.
The wire grid is sandwiched between the hypotenuses of the two prisms that make up the cube. Then, optical cement is used to bind the two prism halves together (refer to the diagram above). The engraved dot on the top of the cube indicates the prism with the wire grid polarizer. Light can be input into any of the polished faces to separate the s- and p-polarizations. One possible orientation is engraved on the top of the cube. Please refer to the BS Cube Mounting tab above for information on mounting options and compatibility. This beamsplitter cube is AR coated for 400 – 700 nm (Ravg < 0.5% @ 0° AOI).
Parameter
Basic Parameters
Spectrogram
| Product ID | PA04012 |
| Design Wavelength | 400 – 700nm |
| AR Coating | Ravg<0.5% @ 0° AOI for 400 – 700nm |
| Material | N-BK7 |
| Extinction Ratioa | Tp/Ts > 1 000:1 @ 0° – 5° AOI Tp/Ts > 100:1 @ 0° – 25° AOI |
| Transmission | Tp > 75% (Avg.) @ 0° AOI for 400 – 700nm |
| Reflectance | Rs > 70% @ 0° – 25° AOI for 400 – 700nm |
| Transmitted Beam Deviation | <5 arcmin |
| Reflected Beam Deviation | 90° ± 5 arcmin |
| Clear Apertureb | >22.9mm x 22.9mm |
| Transmitted Wavefront Error | <λ/4 @ 633nm |
| Surface Quality | 40-20 Scratch-Dig |
| Dimensions (L=W=H) | 1″ (25.4mm) |
| Dimensional Tolerance | +0.00mm / -0.25mm |
Feature
- Transmits P-Polarized Light and Reflects S-Polarized Light
- Unmounted 1″ Polarizing Beamsplitter Cube
- Large Field of View
- High Extinction Ratio
