Polarized Light -- Idea for headlight safety

[FactChecker]

I would be very surprised if linear polarisation (as in camera filters) were used for this sort of project.

Yes. I was only responding to the hypothesis that only reflections from metal polarized a reflection. My experience from using linear filters refutes that.

 

[sophiecentaur]

It’s certainly easier to discuss linearly polarized light and to make predictions. CP is just another step. (Much easier - along with a lot of other EM wave questions- when applied to RF type wavelengths and bits of metal wire)

 

[Keith_McClary]

There is some research on polarized LEDs:

Here, we demonstrate light-emitting diodes presenting high-brightness polarized light emission by combining the polarization-preserving and directional extraction properties of embedded photonic-crystals applied to non-polar gallium nitride.

https://www.nature.com/articles/lsa201222

 

[sophiecentaur]

There is some research on polarized LEDs:

https://www.nature.com/articles/lsa201222

That is an interesting article but may not be too much related to a system that (imo, at least) would benefit more from circular polarisation than from linear.

 

[Eric Bretschneider]

I have been aware of that since the 1960s (wasn't around in the 1930s, sorry, I bow to your seniority )Nothing of the kind; how much have you experimented? Not much, to guess from your assertion...? Try it! Set up two polarisers at right angles and blow some dust or mist or smoke between them and see how much light gets through; THAT is what you call the whole system falling apart? Some people are very hard to please...

Scattering from airborne particles isn't the problem. It's scratches/defects and dirt on the external optical surface. You can clean and polish your optics weekly or perhaps monthly and have it work, but most people aren't going to bother.