For example, glow-in-the-dark materials (photoluminescent) only emit a green hue regardless of the color of the light shone on the material.

Is there such a material that emits the color of the light received, or the combined colors? For example, if one were to shine a red light on the material, it would emit red, same with yellow, etc.

A mirror only reflects light and doesn't absorb or emit any light.

  • $\begingroup$ Phosphorescent materials emit light only after being "charged" with light of shorter wavelength than the emitted light. $\endgroup$ – Jasper Oct 9 '18 at 19:23

In some versions of cavity ring down spectroscopy a diffusely reflecting integrating sphere is used. The reflectivity of its “fumed silica” surface is about .999 over a broad spectral range. The material disperses the light very effectively. The light hits the surface and rattles around in the surface’s microscopic nooks and crannies. This is effectively absorption and remission at the same wavelength.


  • $\begingroup$ Thanks for this. Would it disperse light from all sides of the object, e.g. if I shine a light on the front would be back be illuminated? $\endgroup$ – Questioning Oct 10 '18 at 1:53
  • $\begingroup$ @Questioning if it were made thin enough ( < mm ) $\endgroup$ – creillyucla Oct 10 '18 at 5:02
  • $\begingroup$ Thanks @creillyucla. Is this stuff a new material or just a discovery about an existing material? It calls itself quartz powder in the document. $\endgroup$ – Questioning Oct 10 '18 at 14:27
  • $\begingroup$ @Questioning it's just micron-sized glass particles as far as I can tell (heard a talk once about this stuff). A simple ground-glass diffuser would have a similar effect: thorlabs.com/NewGroupPage9.cfm?ObjectGroup_ID=6337 $\endgroup$ – creillyucla Oct 10 '18 at 16:52

All materials can only emit light of wavelengths that they can also absorb. The same optical degrees of freedom are responsible for absorption and emission.

  • 4
    $\begingroup$ OP is asking for that property across a wide spectral range. $\endgroup$ – JMLCarter Oct 9 '18 at 19:34

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