# [OPTICS] Faraday Rotator with waveplates

• MarkIt
In summary, the conversation discusses the attempt to replicate the effect of a 45° Faraday rotator using waveplates instead. The main book being used is "Polarized Light" by Goldstein, but there are discrepancies in the matrix formulas between different sources. The idea of using a lambda/4 waveplate + lambda/4 waveplate rotated by 45° on the Poincaré sphere is proposed, but the mathematical results using Jones calculus do not support it. The conversation also mentions the use of a half wave plate tilted by pi/8 as a possible solution.
MarkIt
Hi all

I'm trying to replicate the effect of a 45° Faraday rotator using a series of waveplates instead.

I've encountered some difficulties using the jones matrix notation, due to the differencies of the matrix formulas between the books I'm referring to.

The main book I'm using is: "Polarized Light" by Goldstein.

By viewing the problem on the Poincaré sphere I think the solution is a lambda/4 waveplate + lambda/4 waveplate rotated by 45°

But the matematical results via jones calculus don't support my idea.

I hope you can help me.

Best regards

Mark

In my experiment I don't use the backward propagation of the light, I only use the forward one. My goal is to achieve the same 45° polarization rotation using the waveplates instead.

Thanks for the help, I think the closest solution is a half wave plate tilt by pi/8. The resulting jones matrix has the same values of the rotator one, but differs in 2 signs.

Yes, a single halfwave plate is the most straightforward way to rotate a linearly polarized beam.

p.s. welcome to Physics Forums!

Thank you very much! :)

## 1. What is a Faraday Rotator?

A Faraday Rotator is a device that uses the Faraday Effect to rotate the polarization of light passing through it. It typically consists of a piece of glass or crystal placed in a strong magnetic field.

## 2. How does a Faraday Rotator work?

The Faraday Effect is a phenomenon where the polarization plane of light is rotated when passing through a material in a magnetic field. The amount of rotation is dependent on the strength of the magnetic field and the length of the material. By controlling these variables, the polarization of light passing through the Faraday Rotator can be rotated to a desired angle.

## 3. What are waveplates and how are they used in combination with Faraday Rotators?

Waveplates, also known as retarders, are optical elements that can change the polarization state of light passing through them. In combination with a Faraday Rotator, they can be used to control the polarization of light before and after it passes through the rotator. This allows for even more precise control of the polarization of light.

## 4. What are the applications of Faraday Rotators with waveplates?

Faraday Rotators with waveplates are commonly used in optical communication systems, such as fiber optic networks, to control the polarization of light signals. They are also used in laser systems, optical switches, and other optical devices where precise control of polarization is necessary.

## 5. How does the temperature affect the performance of Faraday Rotators with waveplates?

The performance of Faraday Rotators with waveplates can be affected by temperature. The materials used in these devices can have temperature-dependent properties, which can cause changes in the rotation of polarization. To mitigate these effects, temperature compensation techniques may be used, such as using materials with opposite temperature coefficients or using feedback control systems.

• Electromagnetism
Replies
5
Views
2K
• Quantum Physics
Replies
1
Views
845
• Optics
Replies
8
Views
4K
• Other Physics Topics
Replies
10
Views
3K
• Optics
Replies
5
Views
2K
• Special and General Relativity
Replies
12
Views
2K
• Classical Physics
Replies
9
Views
6K
• Mechanics
Replies
10
Views
1K
• Linear and Abstract Algebra
Replies
2
Views
2K
• STEM Career Guidance
Replies
4
Views
2K