Recovering polarized light

In summary, the conversation discusses evanescent waves and their ability to penetrate through some mediums and be recovered. An example is given of sound passing through water, air, and then back into water. The question is then posed about whether polarized light can be recovered in the same manner. The expert explains that polarized light can be recovered, but a significant portion may be lost in the process. They also mention TIRF as an example of recovering evanescent waves. The link between evanescent waves and recovering polarization is not fully understood. The conversation then delves into the polarization state of light that tunnels through during frustrated total internal reflection.
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I was curious; having gone through a class covering Waves, in various forms encountered, we covered evanescent waves. These waves seen to be able to penetrate through some mediums, even able to be recovered. An example might be sound passing through water, then air, and then back into water.

My question is, can one recover polarized light along this line of reasoning, that is, restoring the light to its unpolarized condition?
 
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GPS443556 said:
I was curious; having gone through a class covering Waves, in various forms encountered, we covered evanescent waves. These waves seen to be able to penetrate through some mediums, even able to be recovered. An example might be sound passing through water, then air, and then back into water.

My question is, can one recover polarized light along this line of reasoning, that is, restoring the light to its unpolarized condition?

In most cases (camera filters, sunglasses) light is polarized by filtering out the light of the other polarization and passing only the desired polarization.

So, if you have unpolarized light coming into the filter, you have (at most) 50% polarized light being transmitted. The rest is reflected or (usually) absorbed.

You may be able to turn the polarized light that was transmitted back into unpolarized light, but the 50% (or more) that was reflected or absorbed is gone for all practical purposes.

I suppose if it is reflected, you can try and set up an optical system of mirrors to catch it and recombine it again.
 
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Sound going from water to air does not suffer total internal reflection so no evanescent waves.
The speed of sound in water is higher than in the air, not the other way (as it is for light).

I don't understand your link between evanescent waves and "recovering polarization".

An example of "recovering" the evanescent waves may be the technique called TIRF (Total Internal Reflection Fluorescence) where the evanescent waves are used to excite fluorescence of some beads or cells with dyes situated close enough to the interface.
 
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GPS443556 said:
I was curious; having gone through a class covering Waves, in various forms encountered, we covered evanescent waves. These waves seen to be able to penetrate through some mediums, even able to be recovered. An example might be sound passing through water, then air, and then back into water.

My question is, can one recover polarized light along this line of reasoning, that is, restoring the light to its unpolarized condition?

Evanescent waves are not polarized in the usual sense- they are nonpropogating waves. They can be 'recovered' (frustrated total internal reflection is one example, total internal reflection fluorescence microscopy is another).

But you do ask an interesting question- given polarized light undergoing frustrated total internal reflection, what is the polarization state of the light that 'tunneled' through? It seems to be identical to the original polarization, but I need to read the article more closely:

http://scholarworks.uno.edu/cgi/viewcontent.cgi?article=1071&context=ee_facpubs
 

1. What is polarized light?

Polarized light is light that has a specific orientation of its electric field. This means that the waves of polarized light all vibrate in the same direction, which is perpendicular to the direction of the light's propagation.

2. How is polarized light created naturally?

Polarized light can be created naturally through a process called scattering, where light waves are scattered by particles in the atmosphere, such as air molecules or water droplets. This scattering causes the light to become polarized in a specific direction.

3. What are the different methods for recovering polarized light?

There are several methods for recovering polarized light, including the use of polarizing filters, birefringent materials, and polarization-sensitive detectors. These methods work by selectively allowing only polarized light to pass through or be detected.

4. Why is recovering polarized light important in scientific research?

Polarized light can provide valuable information about the properties of materials and their interactions with light. By recovering polarized light, scientists can study the structure, composition, and behavior of different substances, including biological molecules, crystals, and minerals.

5. What are some practical applications of recovering polarized light?

Recovering polarized light has a wide range of practical applications, including in microscopy, photography, and optical communications. It is also used in industries such as mineralogy, geology, and material science for analyzing and identifying different substances based on their polarized light properties.

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