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Pulsed lasers

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Schrecken_Licht said:
I have a pulsed YAG laser, and like an excimer, the beam is of course invisible.  For burning, a pulsed laser (well, this is true of a laser like mine, where you can only fire it once every 30 seconds at the most) is about the worst thing you can use (other than a very low-powered CW laser, of course).  

A huge amount of energy is dumped into each pulse, but the duration is so brief that there really is no chance for any heat to be deposited.  A hit from my YAG is barely enough to light a match (and only when focused, otherwise it simply ablates some of the material off the match head).  However, if you had a laser with a very rapid pulse rate, then the effect on a target would be more akin to that of a CW laser.  There were a couple of pulsed YAGs at the laser shop I worked at that could be run at 200 pulses per second.  At that rate, they could be used to cut metal just like the CW CO2 lasers.
If they have very little burning/cutting ability, what are they used for? And thanks everyone for the pulsed-laser information. I was getting a little over-excited there (multiple-watt pulses every second every minute for 1/2 a second...oh man, if only it were for real...)

-Mark
 

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Well, schrecken's little box has a power of 3kW during the on time, which is very short , and then has to charge for 30 seconds for another shot. :p
 

DNF

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Thanks everybody for the opinions!
It seems like there is no real advantage for burning/ pointing/ beam appeal for pulsed lasers since they are rated for the Average power.
It seems like there is 3 restrictions to the laser diode good operation: Static electricity discharge, Temperature of the diode and current/voltage applied.
Speaking of current/voltage i have noticed that the diode´s life is inversely proportional to the current applied, and that relationship obeys a power-type function( correct me if i´m wrong), where life of diode is equal to a constant times (the current powered by a constant exponent), and the COD current(or smaller than 10seconds life) is about 3X or 4X times the CW rated current. So if i would calculate the average life of the pulsed diode it would give me a smaller number(excluding the temperature and eletrical discharge limits) than the CW, if for example i raise the peak power of a pulsed diode by X2 of CW and limit the duty cycle for 50%, this would give the same average power of the CW, but a smaller life since for double of the power used at the peak, the life would diminish by MORE than a half from the CW( assuming that doubling the power doubles the current applied)
Please correct me if i´m wrong at some point of this idea.
 

Cyparagon

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DNF said:
It seems like there is 3 restrictions to the laser diode good operation: Static electricity discharge, Temperature of the diode and current/voltage applied.
Close enough. I'd have said: voltage, heat dissipation, and power at end facets. The current may be proportional to power at the end facets, but at the end of the day, the damage sustained to the end facets is the deciding factor.

rocketparrotlet said:
What if you pulsed a 200mW so that it was only on for 1/100 of the time? Would the pulses be 100 times the power? That would look pretty cool, like a laser gun, and if it was really producing 20 watts per pulse, that would be insane.

-Mark
This man is describing an electric chair for laser diodes. What heinous crime have they committed oh villainous mastermind?
 




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