Brewster windows are uncoated optical components that are specifically designed to minimize reflection losses for light with a particular polarization. They are typically made of materials like fused silica or sapphire, and their surfaces are precisely angled to achieve a specific angle of incidence, known as Brewster's angle.
At Brewster's angle, the reflection coefficient for light with a particular polarization (usually p-polarized light) becomes zero. This means that almost all of the light of that polarization can pass through the window without being reflected. The other polarization (s-polarized light) is partially reflected.
Applications:
- Laser cavities: They can be used to ensure that the laser beam remains linearly polarized, which is often essential for optimal performance.
- Polarizers: They can be used in combination with other optical elements to create polarizers, which selectively transmit or block light of a particular polarization.
- Optical isolators: They can be used in conjunction with Faraday rotators to create optical isolators, which prevent reflected light from interfering with the operation of a laser or other optical system.
- Optical amplifiers: They can be used to reduce reflection losses in optical amplifiers, which can improve their efficiency and output power.
| Parameter | Bk7 Brewster Window Sheet Fused Silica Brewster Window Sheet | |
| Wavelength Range | 350-2000 nm | 185-2100 nm |
| Dimension Tolerance | +0.0 / -0.1 mm | +0.0 / -0.1 mm |
| Thickness Tolerance | ±0.1 mm | ±0.1 mm |
| Clear Aperture | >85% | >85% |
| Surface Quality | 10/20 | 10/20 |
| Wavefront Distortion | λ/8 | λ/8 |
| Bevel | <0.25 mm * 45° | 0.25 mm * 45° |
| Coating | Customizable based on client request | |




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