Visible Thin Film Coatings

Reynard Corporation provides thin film coatings in the Visible spectrum for a range of applications in the aerospace, commercial and military markets. Types of thin film coatings available in the Visible range include LongWave Pass (LWP), Shortwave Pass (SWP), Dichroic (Color Separation), Attenuation and Anti Reflection (AR) coatings.

Examples of Thin Film Coatings for the Visible Wavelength Range:

• Cold AR (Anti Reflection) for Plastics: Applied at ambient temperatures, this cold AR coating can be applied to plastics, crystals, cemented doublets and other temperature-sensitive materials. The average resulting reflection is typically less than 0.75% in the Visible range at zero degrees angle of incidence. This coating design can be customized for virtually any substrate index.

• Bare Aluminum Coating: This broadband reflection aluminum coating achieves a reflectivity of approximately 88% in the Visible range. Due to the softness of the coating, the mirrors must be handled with great care.

• Protected Aluminum Coating: Protected aluminum mirrors are created by the application of a thin aluminum  coating followed by a protective coating of silicon monoxide, resulting in a hard and durable mirror, meeting all requirements of MIL-M-13508.  In the visible range, their reflectance is typically more than 88%.

• Enhanced Aluminum Coating: Enhanced reflection is created by means of a dielectric multilayer overcoating, on top of the original aluminum coating. The resulting hard and durable mirrors have a reflectance rate of over 93% in the Visible range and meet all requirements of MIL-M-13508.

• Protected First Surface Silver Coating: This broadband high reflectance coating achieves a reflection rate in the Visible range of over 96%.

• Protected Second Surface Silver Coating: This coating is typically used for internal reflection within prisms and mirrors. Protected second surface silver has a reflectance rate of 94% in the Visible range.

• Visible Longwave Pass Filters (LWP Filters – Visible): These longwave pass (LWP) filters are designed to transmit wavelengths in the visible range longer than 50% of the “cut on” values and reflect the shorter wavelengths. Optimized for a zero degree angle of incidence, the transmission rate for these longwave pass (LWP) filters is typically above 85%, with a reflectance rate greater than 98%.  Applications for longwave pass filters include color control in color separators or combiners.

• Visible Shortwave Pass Filters (SWP Filters – Visible): Wavelengths shorter than the 50% “cut on” value for these Visible SWP filters are transmitted, with longer wavelengths being reflected. The transmission extends to about 0.45 times the 50% “cut on” point and reflects out to approximately 1.34 times the 50% “cut on” point. These Shortwave Pass filters can be supplied for all wavelengths, and applications include color separators or color combiners and spectral order sorters.

Visible Range Thin Film Coating Process:

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 50” 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…

Custom Coating Services:

At Reynard, over 80% of our business is custom. Our Visible range thin film coatings can be engineered and customized for your particular application, and in addition we 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. 

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