Question about wire-grid polarizers

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In summary, the conversation discusses the use of polarizers in petrographic microscopes and how they filter unpolarized light. The waves that are parallel to the direction of the metallic wire in the polarizer are absorbed/reflected, while those perpendicular to it are able to pass through. The question is raised about diagonal waves and whether they are able to pass through, which is clarified by understanding that they can be resolved into their vertical and horizontal components. It is explained that the perpendicular components are able to pass through, while the parallel components are absorbed/reflected.
  • #1
Particle-Wave
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Hi, I'm new to this forum, and am not a genius in any way, so I hope you'll be patient with me.

I've been reading up on petrographic microscopes and understand that unpolarized light is filtered through a polarizer in order to get the EM wave electric fields to oscillate in the same direction. As the unpolarized light hits the wire-grid polarizer, those waves that are parallel with the metallic wire in the polarizer will be absorbed/reflected due to the electric fields interactions with the electrons in the wire. Those EM wave electric fields which are perpendicular to the direction of the wire-grid polarizer will be able to pass through it. My question is: What about those waves that are at a diagonal? Will they be able to pass through or not, and why? Every diagram that I have seen shows that ONLY the waves that are perpendicular to the direction of the wire-grid polarizer will pass through, and any deviation will result in those waves being absorbed/reflected.

If anyone can help me with this, it would be greatly appreciated!
 

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  • #2
Please let me know if I'm even making sense!

:redface:
 
  • #3
The diagonal waves are just made up of vertical and horizontal (or rather can be resolved into H+V)
A 45deg diagonal is equal H and V and so on.
 
  • #4
I think I get it now. Their perpendicular components make it through, while their parallel components are absorbed/reflected.
 
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  • #5


Hi there, thank you for your question. It's great to see someone interested in petrographic microscopes and polarizers.

You are correct in your understanding that unpolarized light is filtered through a polarizer to get the electric fields to oscillate in the same direction. As for your question about the wire-grid polarizer, it is important to note that the metallic wires are arranged in a specific pattern, with a specific spacing and orientation. This pattern allows only the electric fields that are parallel to the wires to pass through, while blocking or absorbing any other orientations.

This means that waves at a diagonal will not be able to pass through the polarizer because they do not align with the wires. This is due to the interactions between the electric fields and the electrons in the wires, which can only occur when the fields are parallel to the wires.

I hope this helps clarify your question. If you have any further questions, please don't hesitate to ask. Keep exploring and learning about polarizers and their applications in microscopy!
 

Related to Question about wire-grid polarizers

1. What is a wire-grid polarizer?

A wire-grid polarizer is an optical device commonly used to polarize light. It consists of a thin layer of parallel metallic wires placed on a substrate at a specific angle. When light passes through the polarizer, only the component of light that is parallel to the wires is allowed to pass through, while the other components are blocked.

2. What is the principle behind wire-grid polarizers?

The principle behind wire-grid polarizers is based on the concept of polarization. Light is an electromagnetic wave that vibrates in all directions perpendicular to its direction of propagation. A polarizer selectively transmits light waves that are vibrating in a single direction, while blocking all other directions. The parallel wires in a wire-grid polarizer act as a filter, allowing only light waves that are parallel to the wires to pass through.

3. What are the applications of wire-grid polarizers?

Wire-grid polarizers have a wide range of applications in various fields such as optics, telecommunications, and imaging. They are commonly used in LCD displays, cameras, and polarizing filters for photography. They are also used in scientific instruments to analyze the polarization of light and in optical microscopy to enhance contrast.

4. How do wire-grid polarizers differ from other types of polarizers?

Wire-grid polarizers have a distinct advantage over other types of polarizers in terms of their ability to transmit a high degree of polarization. They also have a wider spectral range, making them suitable for use with a broader range of wavelengths. Additionally, they are more durable and have a longer lifespan compared to other polarizers.

5. Can wire-grid polarizers be used with non-visible light?

Yes, wire-grid polarizers can be used with non-visible light, such as infrared and ultraviolet light. The transmission properties of the polarizer can be adjusted according to the specific wavelength of the light. However, the polarization efficiency may vary for different wavelengths, so it is important to choose the appropriate polarizer for the specific application.

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