Width of a wire grid polarizer

[deep838]

Why is it that the width of a wire grid polarizer has to be less than the wavelength of the wave which I want to polarize? What would happen if the width was a little bit more?

 

[Andy Resnick]

If I understand you correctly, the spacing between the wires of a wire polarizer need to be less than a wavelength to minimize light scattering- you want the field to respond to 'macroscopic' (spatially averaged) properties of the device, not the microscopic structure, similar to how visible polarizers use long-chain molecules to act as an anisotropic medium.

 

[deep838]

If I understand you correctly, the spacing between the wires of a wire polarizer need to be less than a wavelength to minimize light scattering.

how does that reduce the scattering of light.?

 

[Andy Resnick]

The polarizer would then appear to be a homogeneous object, not an array of discrete scatterers.

 

[sardar]

The width of a wire grid polarizer is an important factor in its ability to polarize light waves. This is because the width of the wire grid must be smaller than the wavelength of the light wave in order to effectively polarize it.

This is due to the principle of diffraction, which states that when a wave passes through an opening or around an obstacle, it will spread out and interfere with itself. If the width of the wire grid is larger than the wavelength of the light wave, the diffraction effect will be too strong and the polarizing effect will be greatly diminished.

On the other hand, if the width of the wire grid is slightly larger than the wavelength, the polarizing effect will still occur, but it will be less efficient. This can result in a decrease in the intensity of the polarized light and a decrease in the contrast of the polarized image.

In order to ensure maximum polarization efficiency, it is important to carefully design and manufacture wire grid polarizers with widths that are smaller than the wavelengths of the light waves they are intended to polarize. This allows for optimal control of the polarization of the light, leading to more accurate and reliable results in scientific experiments and applications.