Epoxy with light filter technology to replace traditional but expensive bandpass filters

Optical Filters are used to transmit a preselected-portion of the light spectrum while rejecting all other wavelengths. So why would you want to do that? There are a many applications that use this technology including proximity and gesture sensors, data transmitters, feedback lasers and optical instruments.

The applications themselves depend on the specific wavelengths that are being allowed, and which of the wavelengths is being blocked. 

In the UV range (30-400nm), applications include:
  • UV-ID, label tracking and barcodes
  • optical sensors and instrumentation
  • light therapy and polymer curing


As you move into the visible light (400-700), many applications want to maximize the light output so none of the wavelengths are being blocked. Applications that do use optical bandpass filters in these wavelengths include:
  • Biomedical applications
  • Environmental testing
  • Flame photometry, fluorescence and immunoassays

 Into the infrared (IR) wavelengths (700nm+), applications include:

  • Distributed feedback lasers
  • Opto-couplers, receivers and transmitters
  • Optical, proximity and gesture sensors

All of these optical cut-off filters have typically relied on traditional coated glass filters which are expensive, expensive to assemble over the light-sensing electronics and most importantly, old-fashioned glass filter technology is difficult to miniaturize.

SolEpoxy has recently introduced a revolutionary chemical filter technology that can be incorporated into our world-class yellow-resistant OL10-1 optically clear encapsulant.

The advantages of a chemical filters are:

  • Can be incorporated into ultra-clear epoxies
  • Require fewer process steps (no glass filter fixing)
  • Can be made to any shape required (ie. lenses)

SolEpoxy's light filtering technology has excellent wavelength cut-off performance and a proven track record for many of the optical electronics applications above.

Learn more about our optically clear encapsulants products here and contact us for samples!