[Geezer (OP)]

Light is just high frequency electromagnetic radiation, right? Why can't I stick an antenna (aerial) on my roof to receive it same as I do with Radio One?

[CZARCAR]

try a glass antena & then use a light amplifier on the other end, like a lightbulb

[RD]

Parabolic dish antennae have been used to receive sound via light ... http://en.wikipedia.org/wiki/Photophone

[yor_on]

Don't they use lasers too?

[Geezer (OP)]

BTW, for those who have not already guessed, this is a loaded question  []

[MikeS]

Light, although still photons only covers a limited spectrum of the electro-magnetic frequencies from ultra violet through visible to infra red.  So light is not the same as radio waves which have a much lower frequency.

[Geezer (OP)]

Light, although still photons only covers a limited spectrum of the electro-magnetic frequencies from ultra violet through visible to infra red.  So light is not the same as radio waves which have a much lower frequency.

It's all electromagnetic radiation, so what's to prevent me using an antenna to receive light?

[techmind]

Nothing's to stop you using an antenna to receive light, except that as the wavelength of light is very small (ballpark of 450~650 nanometres) you'll need extremely small elements in your antenna. Compare this to a TV aerial which is designed for receiving UHF radiowaves (500~800MHz) of 0.4~0.6metres wavelength...

Of course, you could make an array of such antenna using similar techniques to those used to etch the circuits on silicon chips. However, if you then want to do something useful with the antenna output, you need to make a 'radio' circuit -or at minimum (for a new-technology solar-cell) a rectifier device- which will work at frequencies of 5.5x10^14 Hz. Good luck with that  []

If we can solve the rectifier problem, then it seems like it'd be a really cool way to make an efficient solar cell. What I haven't worked out is what the terminal voltage would be for 'full sunlight'. This of course has a crucial bearing on the permissable forward-voltage drop of the rectifier... you could wire a few antenna in series to up the volts, but with the short wavelengths you'd soon run into phasing issues and your antenna could fast become unworkably directional.

[MikeS]

I suppose you could consider the rods and cones of our retina to be a sort of radio aerial in as much as they are tuned to specific frequencies and output an electrical signal.

[CliffordK]

You can stick a solar panel on the roof and receive your light 

[graham.d]

The idea of 1/4 wavelength coatings on glass to minimise reflections and to enhance transmission is analagous to a tuned antenna. It is just a different way to look at it. If you are into RF design it is just equivalent to a matching network.

[Geezer (OP)]

Here we go!

http://www.amolf.nl/news/detailpage/article/ultrasmall-antenna-controls-light-beam-at-nanoscale//chash/33c4f0c56984c8fe974fc4dfe6b0bfe6/

[syhprum]

If I build a superhetrodyne receiver to operate at visible light frequencies using the best monochomatic lasers available what is the minimum IF bandwidth I can employ assuming efficient AFC.

[techmind]

Here we go!

http://www.amolf.nl/news/detailpage/article/ultrasmall-antenna-controls-light-beam-at-nanoscale//chash/33c4f0c56984c8fe974fc4dfe6b0bfe6/

I did propose something a bit related to this which I demonstrated with 3cm microwaves in an internal company meeting in Holland 3-4 years ago. I/we did draft a patent proposal, but I'm not sure that we carried it through. There's some very interesting technologies and cool applications which can be conceived in this field - but it's hard to see them being commercially viable in the near future...

[Geezer (OP)]

I/we did draft a patent proposal, but I'm not sure that we carried it through.

Schtum! Schtum! Not the "P" word. Graham will have one of his turns  []

[imatfaal]

I/we did draft a patent proposal, but I'm not sure that we carried it through.

Schtum! Schtum! Not the "P" word. Graham will have one of his turns  []

pot kettle kettle pot  []

[graham.d]

No I won't. I won't even mention the word "patent". Oh,Damn!