Condition for circular-wire polarizer to transmit no light

[Christofer Br]

I want to make a wire grid surface that transmits no light. For that I wanted to use quarter-circular arc wires. My question is what dimensions would I need to apply to the wires, would an arc with radius = wavelength of incident light be sufficient (since then it is the size of a wavelength in both dimensions) , or do i need a more complicated geometry?

 

[davenn]

I want to make a wire grid surface that transmits no light.

wire won't transmit light unless it is directly heated or high current through it, till it glows

you then go on to talk about incident light ... did you really mean reflect light ?

your post is a little confusing, would you like to clarify what it is you are really referring to and give some background to what you are trying to achieve

Dave

 

[Christofer Br]

wire won't transmit light unless it is directly heated or high current through it, till it glows

you then go on to talk about incident light ... did you really mean reflect light ?

your post is a little confusing, would you like to clarify what it is you are really referring to and give some background to what you are trying to achieve

Dave

You have mistaken emission with transmission. The wire will reflect incident light, while absorbing a small fraction of it's energy, therefore transmitting none.

 

[davenn]

You have mistaken emission with transmission.

no I haven't

you have mistaken emission for reflection

emission comes from within, reflection comes from incident EM ( light etc) reflection from surface

The wire will reflect incident light, while absorbing a small fraction of it's energy, therefore transmitting none.

and I seriously doubt the validity of that comment

 

[sophiecentaur]

The wire will reflect incident light, while absorbing a small fraction of it's energy, therefore transmitting none.

Have you actually done any calculations about the required thickness of a "wire" that would behave as you claim? Wire polarisers work fine with microwaves.
This thread reads like a re-run of one that ran only a day or two ago. Double posting is not appreciated on PF.

 

[davenn]

Have you actually done any calculations about the required thickness of a "wire" that would behave as you claim? Wire polarisers work fine with microwaves.

uh huh and opaque to light

 

[sophiecentaur]

uh huh and opaque to light

What about the gaps in between the wires? A wire polarizer for microwaves is more gap than metal.

uh huh and opaque to light

But the gaps in between the grid?

 

[davenn]

What about the gaps in between the wires? A wire polarizer for microwaves is more gap than metal.

yeah true , but he's talking about light, not RF ( microwaves)

But the gaps in between the grid?

I was referring to the wires being opaque

I want to make a wire grid surface that transmits no light. For that I wanted to use quarter-circular arc wires. My question is what dimensions would I need to apply to the wires, would an arc with radius = wavelength of incident light be sufficient (since then it is the size of a wavelength in both dimensions) , or do i need a more complicated geometry?

unfortunately, he makes no reference to the gaps between the wires, rather only the dimensions of the wires themselves
I, like you, would have thought that it was the size of the gaps relative to the wavelength of the light, that were more important as to if the light would pass through or not

@Andy Resnick , @ZapperZ
or someone else more knowledgeable in optics can help out please ??
Dave

 

[sophiecentaur]

I was referring to the wires being opaque

This is turning a bit comedic. A wire on its own doesn't constitute a Polariser. It would just be a scatterer and the scattered EM would have a small polarised component. Is there any reference to this form of polariser that could work at optical wavelengths? I have comment already on the fact that it is essentially a microwave component and there are a lot of octaves needed to get from mm⁺ wavelengths to hundreds of nanometers.
I don't think the OP has grasped the way a polariser would work and he's just flying a kite. He could look at this link for an idea about a real wire polariser.