Attenuation Coatings

At Reynard Corporation we are proud of possessing over 30 years of manufacturing experience, supplying the highest quality optical components and thin film coating services to the aerospace, military and commercial markets. Amongst the thin film coatings we provide are attenuation filter coatings, which can be applied to our own range of high quality optical components and substrates, or may be applied to a substrate that you provide to us. Attenuating filter coatings, at the most basic level, are thin film coatings, which reduce the amount of light energy transmission in an optical system.

Circular Variable Neutral Density Filters or CVND filters, used in optical instruments to vary light. These filters are designed to attenuate light as function of rotation.

Applications:

Attenuation of light energy is crucial to those applications where the transmission of light energy above a certain level will overwhelm or damage the receptor or detector of that light, as for example in many fiber optic applications. Attenuation coatings may be applied to a substrate to create a variety of attenuating filters, including the following:

• Circular Variable Neutral Density Filters, or CVND filters, used in optical instruments to vary light. These filters are designed to attenuate light as function of rotation.
   
• Linear Variable Neutral Density Filters, or LVND filters, also used in optical instruments to vary light, and designed to attenuate light as a function of translation.
   
• Fixed Neutral Density Filters, which may be used in optical instruments to make a fixed adjustment to the amount of light being transmitted.
   
• Apodizing Filters, where density changes in a radial direction. One application for an apodizing filter is to change a Gaussian light distribution to a “top-hat” distribution.

Process:

A thin metallic attenuating film is deposited on the glass, quartz or other substrate. The attenuation is then effected through both the reflection and absorption of the incoming beam by the attenuating metallic coating. These metallic thin film attenuation filters have the highest quality of spectral flatness, that is, they attenuate all the wavelengths in their usable range to the same extent.

At Reynard Corporation we have over 28,000 square feet of manufacturing space where we engineer and manufacture the very highest quality optical components. Our thin film coating facility has 20 vacuum chambers, ranging from an 18” bell jar to a 54” fully automatic box coater, all in a 4000 square foot Class 1000 clean room. Processes include electron beam, ion assisted and resistance source deposition. We have the capability to coat virtually any size and shape up to and including substrates 45” in diameter.

Available substrates include:

• Alon
• BK-7 (borosilicate crown glass)
• Calcium Fluoride (CaF2)
• Fused Silica Germanium (GE)
• KRS5 ( Thallium Bromo-Iodide)
• Sapphire Magnesium Fluoride (MgF2)
• Silicon (Si)
• Zinc Selenide (ZnSe)
• Zinc Sulfide (ZnS)
• Or as provided by the customer.

Coating materials include:

• Copper (Cu)
• Gold Hafnium Oxide (HfO2)
• ITO (Indium Tin Oxide)
• Magnesium Oxide (MgO)
• Nickel (Ni)
• Silicon Monoxide (SiO)
• Silver Titanium Dioxide (TiO2)
• Tantalum Oxide (Ta2O5)
• Zirconium Oxide (ZrO2)
• And many more…

Stock Thin Film Attenuation Filters or Custom Coating Services:

Our thin film attenuation coatings can be engineered and customized for your particular application, and we also have one of the largest and most comprehensive selection of standard and stock precision optical components in the world. Reynard Corporation is the leading global supplier of optical components to the aerospace, commercial and military markets. We take pride in meeting and exceeding our customers’ expectations in concept, design, engineering and fabrication.

Click here to request a quote for attenuation coatings.

Reynard Corporation operates per Military Specification Mil-I-45208A.

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