Neutral density filters (ND filters for short) are filters that attenuate light intensity without changing the energy distribution of the spectrum. Fixed neutral density filters can evenly attenuate light intensity over a wide spectral region, and are coated with a durable metal film. This type of filter can be used in fields such as natural light and lasers. Fixed density filters are divided into absorption and reflection type ND filters and low reflection type ND filters (ND filters). They neutrally attenuate light over a large spectral range, and are particularly suitable for calibration of optical systems. ND filters of special size, density, and wavelength can be customized.
Model:Neutral Density Filters
Specifications: Customized
Material: Optical Glass
Technical Parameters
| Substrate | BK7 、Fused Silica |
| Thickness tolerance | ±0.1mm |
| Clear Aperture | 90% of the total area |
| Parallelism | 3’ |
| Surface quality | 80-50 |
| Optical density standard deviation | ±5% |
| Calibration wavelength | 550nm |
| Design wavelength | 380nm-2000nm (BK7)250nm-2500nm (Fused Silica) |
Standard products
| size(mm) | OD | T% | Substrate |
| Φ12.7 | 1.0 | 10.0 % | BK7 |
| Φ12.7 | 2.0 | 1.0% | BK7 |
| Φ12.7 | 3.0 | 0.1% | BK7 |
| Φ12.7 | 4.0 | 0.01% | BK7 |
| Φ60 | 1.0 | 10.0 % | BK7 |
| Φ60 | 2.0 | 1.0% | BK7 |
| Φ60 | 3.0 | 0.1% | BK7 |
| Φ60 | 4.0 | 0.01% | BK7 |
| 50 * 50 | 1.0 | 10.0 % | BK7 |
| 50 * 50 | 2.0 | 1.0% | BK7 |
Standard products
| size | series | Substrate |
| Φ12.7 | A | BK7 |
| Φ12.7 | B | BK7 |
| Φ25.4 | A | BK7 |
| Φ25.4 | B | BK7 |
| Φ60 | A | BK7 |
| Φ60 | B | BK7 |
| 50 * 50 | A | BK7 |
| 50 * 50 | B | BK7 |
Series Type
| OD | |||||||||
| A | 0.1 | 0.2 | 0.3 | 0.4 | 0.5 | 0.6 | 0.7 | 0.8 | 0.9 |
| T% | |||||||||
| B | 15% | 20% | 25% | 30% | 40% | 50% | 60% | 70% | 80% |
Other dimensions, optical density, wavelength and other parameters can be customized according to customer needs. You are welcome to contact us.
Application fields
It is mainly used in the field where the light intensity needs to be uniformly attenuated in a wide spectral area. This product is suitable for ordinary light sources and laser light sources.
