ND Filters

Neutral Density Filters

Precision Light Control, Without Spectral Distortion

Andover Neutral Density Filters

Precise light attenuation, from UV to IR, with superior spectral uniformity

Neutral Density (ND) filters are precision optical components designed to reduce light intensity uniformly across a specified wavelength range while maintaining the original spectral characteristics. Used in applications ranging from microscopy to infrared astronomy, these filters provide controlled attenuation without spectral distortion.

Andover Corporation engineers ND filters using advanced thin-film technologies to ensure consistent performance across the UV-VIS-IR spectrum. Each filter is characterized by:

Optical Density (OD): Attenuation levels ranging from 0.1 to 4.0
Spectral Range: Consistent attenuation across a specified wavelength region
Transmission Uniformity: Uniform light reduction across the full spectral range

Whether utilizing metallic coatings for broadband applications, absorptive materials for imaging, or infrared-specific coatings for thermal optics, ND filters provide essential control over light intensity in precision optical systems.

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ND Filter Construction Technologies

Neutral Density filters are manufactured using three distinct construction methods, each offering unique performance advantages. Understanding these differences is key to selecting the optimal filter for your application:

Metallic

Utilizes precision metal alloy coatings to achieve high durability and broad spectral coverage from UV through IR. These filters combine absorption and reflection mechanisms to reduce intensity while maintaining excellent environmental stability. Ideal for laser systems and broad-spectrum applications.

Absorptive

Employs specialized glass substrates that absorb light uniformly across their designed spectral range. These filters minimize back reflections and are anti-reflection coated, making them perfect for imaging applications where ghost images must be eliminated.

Infrared

Specifically engineered for thermal and IR applications using specialized coating materials and substrates suitable from short wave IR to thermal IR ranges. These filters maintain neutral density characteristics in the infrared region while providing the durability needed for thermal imaging and IR laser systems.

Using advanced thin-film coating technologies and precision substrate materials, these construction methods achieve optical densities from 0.3 to 3.0 with exceptional uniformity across their designed spectral ranges.

Neutral Density Filter Solutions

Optimized Light Control for Demanding Applications

Every application has unique spectral requirements. Our comprehensive range of bandpass filters spans from proven industry standards to specialized designs for demanding environments and custom specifications. Select from six distinct filter types, each optimized for specific performance characteristics.

Metallic ND

Industry standard for broad-spectrum applications. Our proprietary metal alloy coatings provide exceptional durability and spectral uniformity for consistent performance.

Wavelength Range
250nm - 2000nm
Optical Density Range
0.1 - 4.0
Construction
Metal Alloy Coating

High Durability
Stock Available
Broad Spectrum

Absorptive ND

Premium solution for imaging applications. Anti-reflection coated absorption glass provides superior performance with minimal back-reflections and ghost images.

Wavelength Range
400nm - 700nm
Optical Density Range
0.1 - 4.0
Construction
AR-Coated Absorption Glass

Minimal Reflections
Image Quality
Stackable

ND Filter Sets

Calibrated sets for precise light control. Available in metallic, absorptive, or IR configurations with convenient storage cases and certification.

Set Options
7, 14, or 17 piece sets
Density Range
0.1 - 4.0 ND
Certification
Individual Spectral Data

Calibrated
Storage Case
Cost Effective

IR ND

Specialized filters for infrared applications. Germanium-based construction provides consistent attenuation across the thermal and IR spectrum.

Wavelength Range
2.0µm - 14.0µm
Optical Density Range
0.3 - 3.0
Construction
Metal-Coated Germanium

IR Optimized
Temperature Stable
Custom Options

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