Visible light

[Jeanguypataterubberboot]

If a transmitter transmits a signal at the frequency of visible light. Will the human eye see it at the antenna?

Just curious.

Pierre

 

[Bluejets]

Don't know about anyone else but I still have to use a multimeter to check dc.
Looked at a lot of pcb's and never seen electricity yet.

 

[Harald Kapp]

If a transmitter transmits a signal at the frequency of visible light.

Then it transmits light. You don't use antennas to transmit light, you use lenses or mirrors..

 

[Jeanguypataterubberboot]

So what is the difference between a radio signal at light frequency and light at the same frequency?

 

[(*steve*)]

So what is the difference between a radio signal at light frequency and light at the same frequency?

Nothing.

 

[Harald Kapp]

A radio signal at light frequency is called light.

 

[Jeanguypataterubberboot]

So theoretically you should be able to see the antenna glow?

 

[Hopup]

Just turn lamp on and see if it glows

 

[Ratch]

So what is the difference between a radio signal at light frequency and light at the same frequency?

There is no radio signal at light frequency. The components that make a radio are incapable of interacting with light and vice versa. A radio and lantern operate on far separate frequency ranges.

Ratch

 

[KJ6EAD]

If a transmitter transmits a signal at the frequency of visible light. Will the human eye see it at the antenna?

Just curious.

Pierre

Yes, but a single antenna will be less than 1μm long. The light sources we're familiar with contain vast quantities of optical antennas.

https://www.photonics.ethz.ch/en/general-information/research/optical-antennas.html

 

[FuZZ1L0G1C]

From what I've read up previously (open to correction):
Visible light is made up of photons.
Photons travel in packets called 'quanta'.. (i think).
They are unaffected by magnetic fields.
A photon is a massless particle, with higher energy as frequency increases.
The electron-volt energy ev is the energy that one photon posesses at a given frequency.
The wavelength of light is from about 685 nm (red) to 380 nm (violet).
That's a frequency of 442THZ red to 789THZ violet.
As a nm is 1E-9 m or 1 millionth of a mm, components would be larger than the longest (red) wavelength.
^y Probably smaller than most molecules.
Which is why electron scanning or tunneling microscopes are used for <1um viewing.
So, no, ya cain't.

 

[AnalogKid]

Yes, but a single antenna will be less than 1μm long.

A single wavelength would be less than 1 um long, but an antenna could be any length you want, such as a (large) integral number of wavelengths.

ak

 

[AnalogKid]

Just turn lamp on and see if it glows

Apples and oranges. In terms of the source of the visible light, thermal radiation from a DC-heated resistor is not the same as an RF oscillator connected to an antenna. His question is whether or not the results of the two would be the same.

ak

 

[Harald Kapp]

thermal radiation from a DC-heated resistor is not the same as an RF oscillator connected to an antenna.

I doubt that for the same wavelength you could make a difference between the radiation. Maybe with some very sophisticated equipment by judging from the noise and harmonic content (as you may discern laser light from LED light by the difference in coherence). Only that a heated resistor will emit a broaad spectrum of light, not a "single" frequency.

 

[davenn]

thermal radiation from a DC-heated resistor is not the same as an RF oscillator connected to an antenna

I doubt that for the same wavelength you could make a difference between the radiation.

Actually, AK response is pretty good

You are not going to be transmitting RF at thermal frequencies
Thermal freq's are IR ( Infra-red) RF is much lower

 

[davenn]

If a transmitter transmits a signal at the frequency of visible light. Will the human eye see it at the antenna?

Then it transmits light. You don't use antennas to transmit light, you use lenses or mirrors..

you use filaments in light globes, semi conductor interactions in LEDs to do the transmitting ….. lenses and mirrors just do focussing/reflecting they don't generate light

 

[Harald Kapp]

lenses and mirrors just do focussing/reflecting they don't generate light

I agree I haven't been as precise as I should have been: I was thinking along the lines of beam forming or directional reception.

 

[Harald Kapp]

ou are not going to be transmitting RF at thermal frequencies
Thermal freq's are IR ( Infra-red) RF is much lower

The op's question concerned

a signal at the frequency of visible light.

RF,visible light, infrared etc. all are electromagnetic waves distinct by the wavelength (or freqency, whichever you prefer).
The original question was not about thermal radiation. A laser, for example, can be considered an oscillator at the wavelength of visible light and would fit the op's question better.

 

[AnalogKid]

I doubt that for the same wavelength you could make a difference between the radiation.

I wasn't addressing differences in the radiation, only my interpretation of the OP's original question about the generation of the radiation. If you (or the crazies at NIST) build a sinewave oscillator circuit that oscillates at the frequency of green, will you see green?

ak

 

[Externet]

If a transmitter transmits a signal at the frequency of visible light. Will the human eye see it at the antenna?

The transmitter that transmits a signal at the frequency of light, will be a PN junction like a LED or laser.
The human eye will see the light emitted, but it is not called antenna, it is a light emitter.