Chalcogenide glass poses challenges when it comes to coating due to its unique properties.

  • Chemical Reactivity:  Chalcogenide glasses are known for their chemical reactivity. They tend to react with many materials, including the materials used in coating processes. This reactivity can lead to the degradation of the coating material or cause unwanted chemical reactions that affect the properties of the coated surface.

  • High Refractive Index:  Chalcogenide glasses typically have a higher refractive index compared to conventional glasses. Higher refractive indices can result in increased reflection and refraction at the surface interfaces, making it challenging to achieve the desired optical properties and coatings thickness.

  • Softness and Brittleness:  Chalcogenide glasses often exhibit softness and brittleness, making them susceptible to damage during coating processes. The application of coating layers may exacerbate these issues, leading to cracking, delamination, or other forms of mechanical failure.

  • Adhesion Problems:  Achieving good adhesion between chalcogenide glass and coating materials can be difficult due to the differences in surface energies and chemical compositions between the glass substrate and the coating material. Poor adhesion can lead to the delamination of the coating layers over time, which cannot happen in field-ready optics.

  • Limited Material Compatibility:  The limited availability of coating materials that are compatible with chalcogenide glass further complicates the coating process. Finding materials that can adhere well to chalcogenide glass while providing the desired optical properties can be challenging.

Overall, the unique chemical and physical properties of chalcogenide glass present significant challenges for coating processes, requiring careful selection of coating materials and process parameters to achieve satisfactory results.

That’s where AccuCoat comes in. We succeed in creating coated chalcogenide optics for our customers where others can’t. Our team knows that reliability in the field and even MIL-SPEC needs are critical for your sales and the satisfaction of your end users.


Our coating machines are specifically set up to carefully monitor and manage critical temperatures while your optics are being cleaned, housed.

Because we have an in-house coating engineer (one of our founders), the success of your IR project is even higher when you partner with our team.

Customized or Standard Coatings

With Coated Wavelength ranging from typical 3-5 microns or 8-12 microns, we can also create a design for a narrower or different bandwidths up to 15 microns.

Review our standard coatings offering below as a starting point for your conversation with us.

Standard AR Coating (IR) – AC165 for broadband AR

8-12 Multilayer AR Coating – AC166 – Multilayer AR Coating