Welcome to Laser Pointer Forums - discuss green laser pointers, blue laser pointers, and all types of lasers

Buy Site Supporter Role (remove some ads) | LPF Donations

Links below open in new window

FrozenGate by Avery

Light and sound






Sure! Believe it or not, a lot of devices transmit sound via light.
One common example is the Digital Out signal from DVD players that connect to an amp. This is transmitted by an optical fiber cable.

Here, a red LED is blinking very rapidly (undetectable by human eye). Instead of the LED, we can use a laser. Since a laser beam is coherent, we shouldn't need a fiber cable or anything. Just aim the laser at a sensor and make sure nothing is blocking the way, and there you have it.

I'm sure this technology is being used somewhere, but it's not as common as fiber optic data transmission.

Cheers!

Edit: My teacher explained to us a set up he built that transferred data via laser beams. Similar concept to the SPDIF optical audio transmission.
 
Last edited:
Thanks
Any idea about the power necessary to transmit information at 1km wireless ? And about the losses of light over distance ?
 
Last edited:
Uh... 1Km might be a bit of a stretch. Because there has to be relatively nothing in between, even air pollution can be a problem in long distances. Plus, a laser's divergence will create a fairly big dot at 1Km, which is definitely not the best way to transmit audio.

So sorry to disappoint you, but unless you're talking about 10-50m, audio transmission via a laser beam won't be practical over 1Km.

Cheers!

Edit: you have a far better chance of accomplishing the task with a CB radio for distances of 1Km.
 
Last edited:
It is possible, but you would need a really nice laser with low divergence. It would also be an eye hazard at the powers required.
 
Last edited:
I understand. The thing is, with radio frequences, I don't believe the signal can be sent in one single direction. Anybody can try to catch it, wich is not possible with the light beam.
 
Are these wild ramblings, or do you have an actual project in mind you'd like to tell us about?
 
Aurelienbis said:
I understand. The thing is, with radio frequences, I don't believe the signal can be sent in one single direction. Anybody can try to catch it, wich is not possible with the light beam.
Click to expand...

There's something called a directional antenna. It sends and receives signals along a very very tight angle. (~10 deg I think)

Say if you have an omnidirectional antenna with a 100 radius range, a directional antenna focuses the signal so that it can reach many kilometers.

With the CB radio frequency, you normally can cover 5Km with an onmidirectional antenna. (walkie talkie) Should be able to cover a LOT of range with a directional antenna. Just try not to break any FCC rules.

And yes, as Cyparagon said, do you have something specific in mind?

Cheers!
 
Last edited:
In fact, I was thinking about making a wireless connection between a computer and speakers in a room. As you say, it would be easier to use wifi or radio frequences.
But, I find the use of laser more fun. So I'll see if I can do it anyway.

I was interested in data protection for military or industry use and seeking if someone could use this. For example a cheap way to transmit confidential informations between ground and air, without using a satellite.
 
Thanks for the links.

Troll mode on : I have so good ideas. I must be a genius.
 
Last edited:
Aurelienbis said:
I found this :
Incroyables Expériences [56] Transmission du son par laser 2 / Laser communicator 2 (récente) - YouTube

Look like these kinds don't really know a lot of stuff abound sound and amplification but what they did works.

Sadly, I have no idea which kind of laser they used what's the quality of the sound in real.
Click to expand...

Aurelienbis said:
Thanks for the links.

Troll mode on : I have so good ideas. I must be a genius.
Click to expand...

I question your genius.....

Looks like they know a bit more than you....

Any ordinary person with a basic knowledge of electronics can
easily decipher that video you linked to.

It is a Dollar Store Red (~650nm) Laser modulated by a hand
wound Toroid transformer excited by the MP3 player.

The Solar cell at the Speaker end captures the modulated Laser
beam and sends that signal to the Speaker amplifier...


Jerry

You can contact us at any time on our Website: J.BAUER Electronics
 
Last edited:
Laserbee, one more time you just don't understand what I wrote. I didn't thought I was that bad at english.

It is a Dollar Store Red (~650nm) Laser modulated by a hand
wound Toroid transformer excited by the MP3 player.

The Solar cell at the Speaker end captures the modulated Laser
beam and sends that signal to the Speaker amplifier...
Click to expand...
=> WTF guy ? Do you really think I am that idiot ? Stop trolling me.
If you could speak french, you would undestand what I said. These kids don't know a shit about transistors and amplification.

And where did you read that I didn't understood that ? Seriously ? "It's a red laser" => YOU DON'T SAY ? My question was more about the power required to make it work.

I know know if you think I'm 8 years old or retarded, but I'm not. And you answers are getting on my nerves. I was wrong about maximum voltage and current charge of Li-Ion accumlator, but that's not a reason to think such things.
 
Last edited:
You must log in or register to reply here.


Back
Top