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I have a plastic container and want to make sure that infrared radiation (specifically, in the 750-850 nanometer range) cannot pass through it. Would wrapping it in aluminum foil do the trick? If not, what household material would be best? The fluence of the radiation is around 22J/cm^2.

Thank you very much!

John
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  • I would be quite surprised if your plastic container didn't already block those wavelengths, but I don't know how to find out for sure. – N. Virgo Nov 04 '12 at 04:40
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    Does the container have to allow visible light through? If not then foil would work. If you want a high pass filter, i.e. block wavelengths less than 750nm but allow everything above this wavelength, you'll need to be a bit more cunning. – John Rennie Nov 04 '12 at 09:11
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    You can avoid/reflect incoming infrared radiation, but as the material heats up, it will reirradiate that heat as infrared radiation as well. – user56771 Nov 04 '12 at 03:03

2 Answers2

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The chart for the reflectance of aluminum tells us that it should do the job for you. But it will likely block anything else within that spectral range, see the plot! reflectivity aluminum

elcojon
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    It is worth noting that even when the reflection is not quite 100%, that doesn't mean light can pass through the aluminum foil. The rest gets absorbed, not transmitted. (Unless the aluminum is under ~50 nanometers thick, for visible and near-IR!) – Steve Byrnes Nov 05 '12 at 01:52
  • You can avoid/reflect incoming infrared radiation, but as the material heats up, it will reirradiate that heat as infrared radiation as well. – user56771 Nov 04 '12 at 03:03
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    Not at 750-800nm until it gets very very hot! – Martin Beckett Nov 04 '12 at 18:38
  • @SteveB: Good addition! – elcojon Nov 05 '12 at 18:09
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Any electrically conductive material will block IR. The greater the conductivity, the greater the blocking. Aluminum foil will kill all IR, bot high range and low. Most plastics allow IR to pass through. Glass will bock low frequency IR (red hot), but allow the passage of high frequency (white hot) IR. Hence, the heat of the sun will easily pass into a greenhouse, but once this energy is converted into low frequency heat by the objects within that absorb it, then the resulting low frequency heat is trapped. Hence, the Greenhouse Effect.

Juan Villar
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  • I can't make an answer because of low rep. But a common material is a survival blanket. It is especially designed to block IR. 90% of it. But I don't know at which wavelength. – solsTiCe Dec 18 '20 at 10:13