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IR Neutral Density Filters

  • Reflection type IR ND filters
  • Metal alloy coating
  • Germanium (Ge) substrates
  • Wide wavelength spectra 2.2μm to 15μm
  • Custom Optical Density (OD)
Curves All Inquire Us  

Specifications:

Substrates Germanium Diameter Range Custom
Transmission 10%, 20% or custom Aperture BBAR Coating on back surface S2 Optional
Dimension Tolerance ±0.2mm Clear Aperture +/-0.2mm90% of outside dimension
Surface Quality 80/50 S/D Flatness 2-4 waves per 25mm
Parallelism 3-5 arc minutes Mechanical Unmounted

Metallic-coated infrared neutral density filters (IR ND filters) obtain their optical density from a metal alloy coating on a substrate determined by the wavelength region of interest. Unlike the all-dielectric or absorption type, the metallic type ND filter employs a combination of absorption and reflection to reduce the intensity of light.

Infrared Neutral Density Filters are designed to attenuate radiation over a wide spectral range. These filters are coated on germanium substrates. The ND coating is optimized at 2.2 microns and can be used out to 15 microns.

Curves:

1. Transmission of IR ND filters (Germanium, T=10%, BBAR coating on back surface S2)

 

2. Transmission of IR ND filters (Germanium, T=10%, No BBAR coating on back surface S2)