Has anyone tried this

[CHP]

Has anyone tried modulating the laser at 120Hz, for example, so that when you burn something a humming sound is produced. This hum would be similar to powering a CO2 laser with AC from a neon transformer.

 

[ossumguywill]

First off, I would like to point out that the hum of a regular transformer is a low C, @ 60 Hz, not 120. And second, this would only work if the object resonated to the laser... and they already sell kits that transfer sound just like this...

 

[Mohrenberg]

I feel stupid right now.

 

[ossumguywill]

I feel stupid right now.

why is that?

 

[Laser_Ben]

Has anyone tried modulating the laser at 120Hz, for example, so that when you burn something a humming sound is produced. This hum would be similar to powering a CO2 laser with AC from a neon transformer.

Yes, many industrial lasers are Q-Switched, this is done to produce high energy pulses instead of a continuous output, it makes it easier to cut some materials. The rate it is pulsed at depends on the cavity, and there are ideal frequencies which will produce maximum power or maximum energy.

Some can be very low pulse rate while others can be very high. My Lightwave 210G runs best at 7khz for power and about 500hz for energy. The 500hz has to do with the upper state lifetime of the gain medium.

If you guys would like me to do a writeup on q-switching, I would be happy to do so, lemme know.

 

[photonaholic]

If you guys would like me to do a writeup on q-switching, I would be happy to do so, lemme know

please do....

 

[CHP]

First off, I would like to point out that the hum of a regular transformer is a low C, @ 60 Hz, not 120. And second, this would only work if the object resonated to the laser... and they already sell kits that transfer sound just like this...

1) If I drive a CO2 laser with AC from 60Hz I get 120 pulses per second. You get 2 discharges per cycle.

2) I've done this exact thing with a focused CO2 laser. You do hear a noise from the burning target.

3) When material heats, it distorts and hence the sound. By hitting a target with pulses you are forcing it to distort - just like knocking on a door - the door isn't resonating to the frequency of your knock, but providing its impulse response to each impulse of your knock.

 

[CHP]

Yes, many industrial lasers are Q-Switched, this is done to produce high energy pulses instead of a continuous output, it makes it easier to cut some materials. The rate it is pulsed at depends on the cavity, and there are ideal frequencies which will produce maximum power or maximum energy.

Some can be very low pulse rate while others can be very high. My Lightwave 210G runs best at 7khz for power and about 500hz for energy. The 500hz has to do with the upper state lifetime of the gain medium.

If you guys would like me to do a writeup on q-switching, I would be happy to do so, lemme know.

I wasn't think Q-switched, although I think this would be a good writeup. Some commercial laser drives have a TTL modulation input, and I was curious if someone tried modulating their laser. I didn't know if the modulated focused power density from a high power red LD would be enough to force a sound from the target. I wasn't thinking about super pulsing the LD either where instead of running at 400 mA DC you would run at 800mA peaks for a 50% duty cycle.

If power density is sufficient to produce sound, the laser's current can be analog modulated with sound, music, etc. to play music while you are burning something. Maybe we can hook it up to an ipod and called it the I-laser?????

 

[Laser_Ben]

If power density is sufficient to produce sound, the laser's current can be analog modulated with sound, music, etc. to play music while you are burning something. Maybe we can hook it up to an ipod and called it the I-laser?????

That is the best fucking idea I have heard in a long time!

 

[Benm]

I have tried using ~200 mW red lasers in pulse modulation, duty cycles varying from a few percent to 99% or so, with frequencies in the audible range (few kHz).

It doesnt actually produce much of a sound from whatever you are burning. Mostly, you dont hear anything at all, sometimes a very slight bit of the operating frequency.

I suppose it has to do with the small peak power of the diode laser - you can't run it at 100x nominal power for a 1% duty cycle since the damage limit is optical, not (just) thermal.

Perhaps its possible to get a more audible result with higher powered diodes, maybe IR that can deliver a few watts peak power, or even the recent high powered bluray diodes. I think it works in principle, just not in practice due to power limitations.

 

[ossumguywill]

1) If I drive a CO2 laser with AC from 60Hz I get 120 pulses per second. You get 2 discharges per cycle.

2) I've done this exact thing with a focused CO2 laser. You do hear a noise from the burning target.

3) When material heats, it distorts and hence the sound. By hitting a target with pulses you are forcing it to distort - just like knocking on a door - the door isn't resonating to the frequency of your knock, but providing its impulse response to each impulse of your knock.

Interesting... I've modulated high-voltage electricity to make a 20-200 hz speaker with a spark , but I always assumed that the heat generated by a pulsed laser would not dissipate fast enough from the target to make significant growth/shrinking.

 

[photonaholic]

Put a row of slightly overinflated black balloons in the way....

It will make sounds, really it will.

 

[Benm]

Only once though

The effect with a laser is nothing like what you get from a modulated spark - that has actual application in plasma tweeters.

 

[Cyparagon]

Yes, it works, but only under the right conditions. I've seen a video of a Ti:Sapphire burning stuff, and it would give a high pitched hum on contact with the material.

 

[Laser_Ben]

Yes, it works, but only under the right conditions. I've seen a video of a Ti:Sapphire burning stuff, and it would give a high pitched hum on contact with the material.

Why the hell would you use an ultrafast system to burn something?

 

[photonaholic]

Maybe precision etching??