Prism Design to Filter Out Infrared Light

AI Thread Summary
Filtering out infrared (IR) light using a prism is theoretically possible, but practical implementation may be challenging due to the variable angles of incidence affecting light spectra. The discussion emphasizes the importance of selecting the right prism material based on the wavelengths that solar cells respond to and the wavelengths transmitted by the prism. Some participants suggest that using a spectral filter instead of a prism would be a simpler and more effective solution for reducing IR light. Additionally, it is noted that most glasses are not transparent below 2 microns, which means they inherently act as IR filters. Overall, while prisms can be considered, spectral filters are recommended for better efficiency in solar panel applications.
Yachtsman
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Is it possible to filter out infrared light using a prism, and if so, how? What is the math involved to do this?

I want to come up with some effective, durable ways to filter out IR light for solar panels, to keep their temperature lower to make them more efficient.
 
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Yachtsman said:
Is it possible to filter out infrared light using a prism, and if so, how? What is the math involved to do this?

I want to come up with some effective, durable ways to filter out IR light for solar panels, to keep their temperature lower to make them more efficient.

I'm not sure there's any math involved at all. Just look at where the visible light ends and block off everything on either side of it. I'd lookup which frequencies your cell is the most efficient at first, though. It might like the IR light.
 
You must choose the prism material carefully by researching the following:
1) What are the wavelenghts that the solar cells respond most stronly to.
2) What are the wavelengths transmitted by the prism material?
3) How much of the required light is absorbd by by your prism material?**
4) If IR is not beneficial to the power produced, try to chose a material that does not transmit IR.
I presume you are worried about the panels overheating from the IR absorption.

If I were doing this, I would skip the prisms (added cost and weight) and just go with an IR filter.
 
A prism is not ideal because the angle of incidence and the position at which the light strikes the prism is inherently variable. This results in a plethora of spectra superimposed on one another which largely prohibits spatial filtering.

I agree with daqddyo1; a spectral filter is by far a simpler solution here.

Also, keep in mind that most glasses are not transparent below a wavelength of 2 microns in any case, so any prism would effectively act as an IR filter anyway.

Claude.
 
I would like to use a pentaprism with some amount of magnification. The pentaprism will be used to reflect a real image at 90 degrees angle but I also want the reflected image to appear larger. The distance between the prism and the real image is about 70cm. The pentaprism has two reflecting sides (surfaces) with mirrored coating and two refracting sides. I understand that one of the four sides needs to be curved (spherical curvature) to achieve the magnification effect. But which of the...
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