How does light passing through a QWP become unpolarized?

Dec 14, 2011

CH1991

Homework Statement

http://i.imgur.com/awJgh.png

Homework Equations

The Attempt at a Solution

Is just because lights out of QWP become unpolarized so 0.5*0.5 = 0.25?
Thanks!

Dec 14, 2011

Spinnor

Gold Member

Half the light makes it past the first polarizer, to figure out how much gets past the second see,

http://en.wikipedia.org/wiki/Polarizer#Malus.27_law_and_other_properties

Hope this helps.

1. What is a QWP polarizer and how does it work?

A QWP (quarter-wave plate) polarizer is a device that can manipulate the polarization of light. It consists of a thin, birefringent material that causes incoming light to split into two orthogonal polarizations. The light then travels through a quarter-wave plate, which delays one polarization by a quarter of a wavelength. This results in the two polarizations becoming in phase, producing circularly polarized light.

2. What are the applications of QWP polarizers?

QWP polarizers have a wide range of applications in optics and photonics. They are commonly used in optical instruments, such as microscopes and telescopes, to control the polarization of light. They are also used in displays, such as LCD screens, to produce polarized light. QWP polarizers are also used in optical communication systems and in various scientific experiments.

3. How do you choose the appropriate QWP polarizer for a specific application?

The appropriate QWP polarizer for a specific application depends on several factors, including the wavelength of light, the desired degree of polarization, and the required transmission efficiency. It is important to choose a QWP polarizer that is compatible with the wavelength range of the light source and has a high extinction ratio and transmission efficiency for the desired polarization state.

4. Can QWP polarizers be used with other polarizing elements?

Yes, QWP polarizers can be used in conjunction with other polarizing elements, such as linear polarizers or another QWP polarizer. This can help to further control the polarization of light for specific applications. However, it is important to note that the use of multiple polarizing elements can result in a decrease in transmission efficiency.

5. How do you maintain and clean QWP polarizers?

To maintain and clean QWP polarizers, it is important to handle them carefully and avoid any scratches or damage to the surfaces. They can be cleaned using a soft, lint-free cloth and a mild cleaning solution, such as isopropyl alcohol. It is important to avoid using harsh chemicals or abrasive materials, as this can damage the polarizer. Additionally, QWP polarizers should be stored in a clean, dry environment to prevent any buildup of dust or debris.