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Q switch curiousity.

Ilotrophic

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I am just curious. Have no genuine purpose other than I can't find my answer elsewhere. How many Watts do the average Q-switch medical laser's have? Ones mainly used for removing tattoo's is what I'm talking about.

Note* I have no intention in getting one of these. I was just wondering.
 

Jollyrajer73

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They range from 2 Watts all the way up to 1 Kilowatts. They vastly range in wavelengths such as 438, 440, 447, 473, 555, 561, 750-1000, 946, 1313, 1320, 1342nm

lol :wtf:
 

FrothyChimp

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Pulsed lasers are not measured in watts. The watt really has no meaning in that context because it does not pulse over a full second. The Joule is the measure of energy used for pulsed lasers. Pulsed lasers are incredibly energetic. The q-switch allows the cavity energy to build to maximum and releases the full cavity energy in a pulse lasting anywhere from 10ns or so to 200ns depending on the design. Medical lasers generally range from mJ to J pulses depending on what they are to be used for. The last pulsed system I operated output 1.52mJ pulses at a wavelength of 532nm. This would punch holes in thin steel. I happen to love pulsed lasers. They are much more dangerous however due to the very high emission energies involved plus the electronics are often comprised of dangerous capacitor banks for driving arc or flash lamps (older systems).
 

Jollyrajer73

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Okay smart one well he wanted his question answered so I answered it :p

Good looks though

Technically yes the lasers are not measured in watts :toilet:
 

jimdt7

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Pulsed lasers are not measured in watts. The watt really has no meaning in that context because it does not pulse over a full second. The Joule is the measure of energy used for pulsed lasers. Pulsed lasers are incredibly energetic. The q-switch allows the cavity energy to build to maximum and releases the full cavity energy in a pulse lasting anywhere from 10ns or so to 200ns depending on the design. Medical lasers generally range from mJ to J pulses depending on what they are to be used for. The last pulsed system I operated output 1.52mJ pulses at a wavelength of 532nm. This would punch holes in thin steel. I happen to love pulsed lasers. They are much more dangerous however due to the very high emission energies involved plus the electronics are often comprised of dangerous capacitor banks for driving arc or flash lamps (older systems).
Nice answer :gj:
You deserve it +1 :beer:

Jim
 

AJ Pierson

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Okay smart one well he wanted his question answered so I answered it :p

Good looks though

Technically yes the lasers are not measured in watts :toilet:

Hey Jollyrajer73, while the frothy one may be correct in the strictest sense, you are not incorrect in practical terms. The manufacturer specs for pulsed lasers sometimes list figures for average output power, in which case, the unit is indeed the Watt.

And, speaking of "good looks", I hope for your sake that the sweet chiquita in your avatar is your gf. She's gorgeous. And by that, I mean take one look and fall outta your chair without noticing gorgeous. Relax, not lookin to steal her from ya, I'm on the East coast (but, man oh man if I wasn't.......). :D


Edit 2: HMMMMM, something just occurred to me: :thinking: You might actually BE the sweet chiquita in that avatar (posing with a guy friend). If so, please excuse my assumption.
 
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DrSid

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1.52mJ can punch steel ? It's the same energy as 1.52mW over 1 second right ?
 

FrothyChimp

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This is why pulsed lasers are not measured in watts. What is the equivalent power if that energy is not over 1 second but over 80ns (pulse duration)? You will see why it will punch a hole in thin steel. Your solution should have a kW after it.
 

arcaneinsomniac

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1.52mJ/50ns = 30.4kW. Of course that's if it didn't "rest" between firing pulses at all.

Suppose there are 5000 pulses per second. 1.52mJ * 5000 / 1s = 7.6 watts.

The difference between this laser and a 7.6 watt Continuous Wave laser is that it puts out 30kW for a fraction of the time and recovers the rest of the time, averaging out to 7.6W overall. But you'll be slicing away a tiny chunk of steel each pulse, rather than barely heating it up at all.
 

DrSid

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Oh if it does 5000 such pulses per second, then fine.
 

arcaneinsomniac

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Oh if it does 5000 such pulses per second, then fine.
Well I have no idea, I'm just illustrating the math. 50ns is 50 billionths of a second. There are 20,000,000 of those intervals in one second. I also picked 50ns out of thin air as well.

The reason it cuts steel is that for a 20-millionths (1/20 of a millionth) of a second the laser is a 30KW laser. Then it's off for a while. Then back on at 30KW.
 
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DrSid

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Yeah, but generally it's all about transfered energy. 1J pulse may by 100ns short, or 1s short .. and it should generally have same effects. With steel it won't be same, as steel conducts heat well, and short pulses will be much more effective .. but IMHO not 1000 times.
I doubt ONE 1.52mJ pulse can burn steel, or anything any well. I guess you have all seen SSY-1 videos .. those are single pulses about 0.1 J. And they are just on border of denting steel.
 

Ilotrophic

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This is why pulsed lasers are not measured in watts. What is the equivalent power if that energy is not over 1 second but over 80ns (pulse duration)? You will see why it will punch a hole in thin steel. Your solution should have a kW after it.
I just happened to stumble on one of your video's on youtube. The 10W green dpss.
I must say sir that is most impressive.
:drool:
 




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