Understanding Polarization in Light: Exploring the Concepts and Misconceptions

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In summary, the concept of polarization can be confusing, but it is essentially the alignment of light waves in a specific direction. Polarizing films and polarizers only allow light waves oscillating in certain directions to pass through, while blocking others. In the classic case of three polarizers, each one allows a different direction of oscillation to pass through, resulting in only one specific direction being able to pass through all three.
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kdm06d
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Hey--

Im an engineering student having trouble with the polarization concepts.

So let's say you have a ray of light traveling and it travels through a polarizing film with its respect to the horizontal, now only the x-component of the light vector passes through...

I believe my understanding of this is wrong..But understand I do know the idea behind the ray being an oscillating wave etc...

So first off, how can the polarizing angle only allow an x-component of something which is oscillating up and down, without preventing further oscillation?

Secondly, in the classic case of three polarizers with the middle being rotated to allow light to pass through all three, my confusion deepens.

If my previous theory were correct (which I do not believe it to be)... Then the first film would allow let's say only the x component through. Then does the middle 45 degree tilted film somehow rotate the x-direction moving vector of light to more of an x=y type slope, then the third allows only the y-direction vector through?

I do not believe I am going about thinking of this in the proper manner, I was hoping someone on here could understand my view point and perhaps see where I am misunderstanding...

Thanks for any help
 
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Hi there!

I can understand why you might be having trouble with polarization concepts. It can definitely be a bit confusing at first. Let me try to explain it in a different way that might make more sense to you.

First, let's talk about what polarization actually is. When light travels, it is made up of electromagnetic waves that are oscillating in different directions. When these waves are all oscillating in the same direction, we say that the light is polarized. This polarization can be in any direction, not just horizontal or vertical. So when we talk about a polarizing film, what we are really talking about is a material that allows light waves oscillating in a specific direction to pass through, while blocking waves oscillating in other directions.

Now, when you say that the polarizing film only allows the x-component of the light vector to pass through, what you are essentially saying is that the film is aligned in such a way that it only allows light waves oscillating in the x-direction to pass through. This does not mean that the light wave itself is restricted to only oscillating in the x-direction. It simply means that the film only allows light waves oscillating in the x-direction to pass through, while blocking waves oscillating in other directions. So the light wave can still oscillate up and down, but only the x-component of that oscillation is able to pass through the film.

Now, let's talk about the classic case of three polarizers. In this scenario, the first polarizer will only allow light waves oscillating in a specific direction to pass through. The second polarizer, which is rotated at a 45 degree angle, will allow light waves oscillating in a different direction to pass through. So in this case, the second polarizer is not rotating the x-direction moving vector of light to more of an x=y type slope. Instead, it is simply allowing a different direction of oscillation to pass through. And finally, the third polarizer will only allow light waves oscillating in yet another direction to pass through. So in the end, only light waves oscillating in this specific direction will be able to pass through all three polarizers.

I hope this helps to clear up your confusion. If you have any further questions or need clarification, please don't hesitate to ask. Keep up the good work in your engineering studies!
 
  • #3
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Dear engineering student,

Thank you for reaching out and expressing your confusion with the concepts of polarization in light. I understand that this can be a challenging topic to grasp, but I am here to help clarify some of your misconceptions.

Firstly, your understanding of the polarizing angle only allowing an x-component of light to pass through is not entirely correct. Polarization is a result of the electric field of light oscillating in a particular direction. When light passes through a polarizing film, it only allows the component of the electric field that is aligned with the orientation of the film to pass through. This means that the remaining components of the electric field, which are perpendicular to the orientation of the film, are blocked. So, the polarizing angle does not change the direction of the light's oscillation, but rather filters out certain components of the electric field.

Secondly, in the case of three polarizers with the middle one rotated, the polarizing angle of each film determines which components of the electric field can pass through. The first film will allow only the x-component to pass through, as you mentioned. The middle film, being rotated at a 45 degree angle, will allow both the x and y components of the electric field to pass through. This is because the orientation of the film is now aligned with both the x and y directions. And finally, the third film will only allow the y-component to pass through, as it is oriented perpendicular to the x and y directions.

I hope this explanation helps clarify your understanding of polarization in light. It is important to remember that polarization is a result of the electric field of light, not its direction of travel. If you have any further questions or concerns, I would be happy to assist you. Keep exploring and learning about this fascinating topic! Best of luck in your studies.
 

FAQ: Understanding Polarization in Light: Exploring the Concepts and Misconceptions

What is polarization in light?

Polarization in light refers to the orientation of the electric field vector of an electromagnetic wave. In unpolarized light, the electric field vector can vibrate in any direction perpendicular to the direction of propagation. However, in polarized light, the electric field vector is restricted to vibrate in a specific direction.

How is polarization in light created?

Polarization in light can be created through various methods, such as reflection, refraction, scattering, and birefringence. For example, when light reflects off a non-metallic surface at a specific angle, the reflected light becomes polarized. Similarly, when light passes through certain materials, such as polarizing filters or crystals, it can also become polarized.

What are some common misconceptions about polarization in light?

One common misconception is that polarized light is a different type of light than unpolarized light. In reality, polarized and unpolarized light are both forms of electromagnetic radiation. Another misconception is that polarized light is always perfectly aligned. In reality, polarization can vary in degree, and even perfectly polarized light can become depolarized when it interacts with certain materials.

How is polarization in light used in everyday life?

Polarization in light has several practical applications in everyday life. For example, polarized sunglasses use a polarizing filter to reduce glare from reflected light, making it easier to see in bright environments. Polarizing filters are also used in photography to reduce glare and improve the contrast of images. Additionally, polarized light is used in LCD screens found in electronic devices like TVs and smartphones.

How does understanding polarization in light benefit scientific research?

Understanding polarization in light is crucial in many areas of scientific research. It allows scientists to analyze the composition and properties of various materials, such as crystals and biological tissues. It also plays a significant role in the study of celestial bodies, as polarized light can provide valuable information about the composition and structure of objects in space. Furthermore, polarization in light is essential in fields such as quantum mechanics and telecommunications.

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