High-contrast 45° Polarizing Beamsplitter Plate
The polarizing beam splitter plate separates incident laser beams of different wavelengths by polarization. Its right-angle surface is coated with a single-wavelength polarization splitting film, while the wedge surface is coated with an anti-reflection film. At a 45° incidence angle, p-polarized light is transmitted and s-polarized light is reflected. The coating is optimized for 45° incidence; deviation from this angle will degrade the nominal extinction ratio. The exit surface features a 30 arcmin wedge angle to eliminate ghost reflections, and a side arrow mark indicates the beam propagation direction.
Manufactured from fused silica, this splitter plate exhibits a higher laser damage threshold compared with coated prisms. Compared with Brewster beam splitters, its 45° incident angle enables simpler installation and better compatibility with compact optical layouts.
- Extinction Ratio (Tp:Ts): > 1000:1
- Exit Surface Wedge Angle: 30 arcmin
Parameters
| Material | UV Fused Silica |
| Dimension Tolerance | + 0/ -0.1 mm |
| Thickness Tolerance | ± 0.1 mm |
| Surface Quality | 40-20 |
| Flatness | λ/4@632.8 nm |
| Wedge Angle | 30 ± 10 arcmin |
| Extinction Ratio* | Tp/Ts > 1000: 1 |
| Transmission | Tp > 95% |
| AOI | 45° |
* Extinction ratio is the ratio of max to min transmittance of linearly polarized light, tested at 45° incidence angle.
Model
| Wavelength, nm | Dia., mm | Clear aperture, mm | Damage threshold |
| 1064 | Φ25.4 | > Φ23 | 4 J/cm2(10 ns,10 Hz@1064 nm) |
| 633 | 4 J/cm2(10 ns,10 Hz@633 nm) | ||
| 532 | 4 J/cm2(10 ns,10 Hz@532 nm) |