Acrylic (PMMA) for NIR Transmission in Optical Windows, Sensor & Camera Covers

03|2024

There are many advantages to using an absorptive acrylic material to control NIR light. 

Autonomous applications such as computer vision, machine vision, robotics, LIDAR and others work best when only the desired lights passes and all the noise is blocked.  For many such applications, acrylic has numerous advantages over a coated piece of glass:

  1. Unlike coating Gorilla Glass or similar clear glass substrates, the coating doesn’t have to block visible light (the absorptive acrylic material does the heavy lifting). Therefore, the coatings become far less complex, more rugged/robust, and far less costly.
  2. Using an absorptive acrylic material to block visible light is a more repeatable, reliable and a more thorough way to do the job vs. asking the coating to do it. The absorptive acrylic material is also completely angle-of-incidence insensitive. The coating is not.
  3. Scratches, digs or chips that might subsequently be introduced to an absorptive type filter after installation would not allow visible light to be transmitted. Damage to any external coating on glass could result in a complete loss of coating performance in the area where the damage has occurred.
  4. Most acrylic filters from JNS come with a highly efficient and durable oleophobic (and solvent resistant) coating, meaning it is far easier to clean.  An oleophobic coating also helps to minimize damage that might be inflicted by the cleaning process itself (which in the case of any optical component, is a pervasive problem).
  5. Acrylic is significantly lighter than glass.  A 25.4mm diameter x 1mm thick piece of cell cast acrylic weights approximately 0.60 grams while the same size piece of Gorilla Glass weighs more than twice as much at approximately 1.27 grams.

JNS offers absorptive acrylic bandpsss filters and protective windows for every application. 

  • NIR longpass filters that block VIS & pass NIR
  • 685 cut filter
  • 850 cut filter
  • 900 cut filter
  • custom bandpass filters such as 1550 for LIDAR