FND-25C02-40 25 mm Dia. Unmounted N-BK7 Visible Reflective Neutral Density Filter; t=2mm 400-700nm
- Type
- Filter
- Subtype
- Neutral Density Filter
- Brand
- OptoSigma
Properties
- Shape
- Circular
- Diameter
- 25 mm
Material
- Name
- N-BK7
- Dispersion Equation
- Sellmeier
- n (λ)
- 1.5185223876207927
- λ
- 550 nm
- B1
- 1.03961212
- C1
- 0.00600069867 μm2
- B2
- 0.231792344
- C2
- 0.0200179144 μm2
- B3
- 1.01046945
- C3
- 103.560653 μm2
FND-25C02-40 25 mm Dia. Unmounted N-BK7 Visible Reflective Neutral Density Filter; t=2mm 400-700nm
This is the FND-25C02-40, a 25 mm diameter unmounted Neutral Density Filter from OptoSigma. The filter is made of N-BK7 Schott, a high-quality optical glass known for its excellent transmittance and low auto-fluorescence.
The filter is designed to provide a uniform attenuation of light across the visible spectrum, specifically within the 400-700nm range. This makes it ideal for applications that require a consistent reduction of light intensity, such as in photography, beam profiling, or laser applications.
The filter features a thickness of 2mm, which is thin enough to minimize optical aberrations while being robust enough for practical use. The front and back surfaces of the filter are coated with Opt FND-40, a reflective neutral density coating that further enhances its light attenuation properties.
The FND-25C02-40 is available in a thin lens shape, which is advantageous in applications where space is limited or where a flat surface is required. The filter is currently in stock and can be purchased directly from the OptoSigma website.