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Dichroic Filters

Complex thin film optical stacks to control the transmission and reflection of light.

Dontech offers a wide array of high energy vacuum deposition systems for applying thin film dichroic coatings to different types of glass, plastic, and crystalline substrates. Performance of coatings is in many cases substrate limited.  Coating processes include DC and AC magnetron sputtering and ion enhanced (IAD) e-beam evaporation.

Dontech manufactures custom dichroic filters for the control of light. Complex, thin optical film stacks are designed and applied to substrates to create discrete reflections and optimize light transmissions over the designated spectrum and incident angles.  Dontech custom dichroic filters are as follows:

  • Narrow band pass
  • Short wave pass (e.g., night vision compatible hot mirrors)
  • Long pass
  • Band rejection/laser blocking
  • Mirrors
  • Beamsplitters


All of Dontech’s dichroic filters are custom.  Dontech designs and produces dichroic coatings to meet the following stringent environmental and quality standards. We also work to internal and customer environmental and optical requirements: 

  • MIL-STD-810 
  • MIL-PRF-13830


Short wave pass dichroic filters are often used for the control of the Near IR (NIR) and deep red in the visible spectrum which is noise from the backlighting system of most LCDs. These sharp cutoff filters block this noise while transmitting high levels of primary visible light (i.e., the RGB components) from the electronic display.  These types of dichroic filters are commonly referred to as “hot mirrors”.  Hot mirrors are commonly used for night vision imaging system (NVIS) compatibility for a full color LCD per MIL-STD-3009. For example, the transmission curve for CN303-11 transmits over 88% of an LCD’s red, green, blue (RGB) components while reflecting over 99% of the energy from 630 to 930 nm.  

Band rejections filters are common in military periscopes and viewing systems used on land or amphibious vehicles which require filters to prevent eye injury to operators from enemy laser targeting systems and temporary blinding systems. These filters are commonly named “laser blocking” filters. Dontech’s laser blocking filters utilize complex dielectric stacks to separate unwanted wavelengths from the desired visible light wavelengths.  

DONTECH & Dichroic Filters

Dontech has extensive engineering and technical support resources that can assist with your dichroic coating selection and design needs. Our technical staff have diverse backgrounds relevant to high-performance display and precision optics markets. For many of our top customers, we function as an extension of their engineering departments, supporting projects from concept to final system delivery. We will integrate our optical filters and other enhancing components into touchscreens, displays and systems to the level that is needed by our customers.

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