- Glows a deep orange upon exposure to infrared radiation.
- Phosphorescent area is approximately the size of the infrared beam.
- Infrared beam finder.
The Harrick Infrared Beam Finder allows viewing of the infrared beam from an FT-IR spectrometer and simplifies alignment of accessories. It contains a tab with a phosphor-based compound that absorbs and "traps" light energy from a short wavelength source (such as a lamp or sunlight), and then releases this stored light in the form of visible light upon exposure to IR radiation. The result is a localized glow of intensity relative to the amount of stored light and to the intensity of the IR incident upon the active phosphor area.