Continuously Variable Neutral Density Filters NDFR-25C-2

Continuously Variable Neutral Density Filters — Model NDFR-25C-2

Continuously Variable Neutral Density Filters

Product Description

• The OD value can be adjusted by rotating the filter angle
• Circular shape with continuously adjustable OD value
• Suitable for working wavelength range of 240-1200 nm

LBTEK Continuous Variable Neutral Density Filters provide linearly adjustable attenuation by rotating the coated area. The structure consists of UV fused silica substrate and a 270° metal (Inconel) coating. The OD value increases linearly in a counterclockwise direction at different angles. This design is suitable for a wavelength range of 240-1200 nm. The OD value range of the continuous variable neutral density filters is 0.04-2.0, 0.04-4.0, or 0.04-6.0. There is a linear relationship between the OD value and the angle θ, satisfying OD = k * θ, where k is 0.0073, 0.0147, and 0.0221, respectively. The available diameters are currently Ø25 mm, Ø50 mm, and Ø100 mm. In addition to standard continuous variable neutral density filters, LBTEK also offers various customization services. For specific customization requirements, please contact LBTEK Technical Support.

Continuously Variable Neutral Density Filters

• OD range: 0.04-2.0, 0.04-4.0, 0.04-6.0
• Coating: Inconel
• Size: Ø25 mm, Ø50 mm or Ø100 mm

LBTEK Continuously Variable Neutral Density Filters are composed of UV-grade fused silica substrates and a full 270° metal (Inconel) coating, designed for a transmission wavelength range of 240-1200 nm. The central aperture diameter of the continuous neutral density filters is uniformly 7.5 mm, facilitating mechanical mounting, and the OD value can be adjusted by rotation. Although classified as reflective neutral density filters, the Inconel coating still absorbs a portion of the incident light. To ensure optimal performance, it is recommended that incident light enters from the side coated with Inconel. Additionally, caution should be taken to avoid contact with this unprotected metal coating, as touching may scratch the unprotected surface. For cleaning, the use of an air blower is recommended.