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FrozenGate by Avery

When will a 1W portable green laser arrive?

For those who aren't quite sure how a peltier cake works it has two sides a hot side and a cold side
too cool
you blow air across the hotside
to heat
you move air across the cool side

the catch 22 is here that the hotside will get hot enough to sear skin well over 150F
so even with a heatsink it will get very very hot (although the heatsink would look cool as hell on the end of a laser)

well the liquid cooled heatpipe system is not all that new they was originally put in powerful laptops but because the piping was enclosed no air really moved over it,
you can have two heatsinks
one normal
one with a cross ribbed
and the one with the cross ribbed surface will cool better then the regular one

as it wil have more surface area to do this then by adding a liqiud heatpipe system you further dissipate the heat

the downfall of a typical heatpipe system is that the piping contains just air and doesn't aide in the heat transfer
 





Peltiers are not a cure all. They are more useful in using them to help assist heat sinks, but they are grossly inefficient. In a handheld pointer, a peltier would not be an option. Even using a peltier with a Qmax rated close to the heatload of the diode and not counting thermal atmospheric loss from no insulation, the current draw to get a DeltaT to be useful would be astronomical. A heatpipe, as I stated in my first post, would be the ONLY alternative, and would allow the heatsink to be remotely mounted toward the rear of the pointer.

I don't really like Peltiers, from a design standpoint. Condensation, hook it up backwards and bake the thing you are trying to cool, electrical failure and it insulates kinda well, apply a temp differential and it generates voltage..... eh. I'd rather use them to assist a cooling system, rather than directly BE one.

Like I said, a 1 watt pointer is doable, for short periods. Extended run times, and you are moving alot of heat and current in a small package. There isn't a booming demand for eyeball shattering handheld pointers.
 
I think it would cost more than $4k :P And about the jumbo IR filters needed for multiwatt DPSS....wouldn't it be easier to use a prism and let refraction separate the IR from the green? :P
 
yeah. you're right, the peltier wouldnt be very effective.

though if u add an enormous heatsink it wouldnt be that "portable".
i really dont know any other techniques to cool something....however i dont think liquid cooling would be an option, that would DEFINITELY make the laser not portable.
 
monel_funkawitz said:
Peltiers are not a cure all. They are more useful in using them to help assist heat sinks, but they are grossly inefficient. In a handheld pointer, a peltier would not be an option. Even using a peltier with a Qmax rated close to the heatload of the diode and not counting thermal atmospheric loss from no insulation, the current draw to get a DeltaT to be useful would be astronomical. A heatpipe, as I stated in my first post, would be the ONLY alternative, and would allow the heatsink to be remotely mounted toward the rear of the pointer.

I don't really like Peltiers, from a design standpoint. Condensation, hook it up backwards and bake the thing you are trying to cool, electrical failure and it insulates kinda well, apply a temp differential and it generates voltage..... eh. I'd rather use them to assist a cooling system, rather than directly BE one.

Like I said, a 1 watt pointer is doable, for short periods. Extended run times, and you are moving alot of heat and current in a small package. There isn't a booming demand for eyeball shattering handheld pointers.
Click to expand...


I knew a peltiers where out pretty much from square one i have used them a few times with grossly undesirable results,
using a oil filled heat pipe system from simulations so far looks like it would work very well, it will be a little cumber some but its trade out for the ability to light a match a mile away <--joke anyway i have the housing be cut at the local machine shop so i am going ahead with the first mock up me and 6 of my engineering buddies are working on the driver small enough to fit in the housing ill have pictures coming soon.
 
Any of you guys remember Dwight Finney's kids running around a garage with two D cell Maglite mods wearing welding helmets and playing Jedi?  Now THOSE were at LEAST 1 watt.  The beam diameters were hugeantic!  If I remember right, Finney was a laser control officer for a Spokane Lumber company at one time.


His lasers, when he got around to them, were fantastic.   I've got the 'jedi' video around here somewhere.  Those lasers were crazy.  Finney was the 'Ralf Ottow' of lasers.


TS
 
Correct me if I'm wrong or just way off track, but doesn't the current orange laser use two diodes?

Is it possible, to collimate two or even more diodes into a single beam? :-? You know, like having two engines in your car! ;D
 
Ace82 said:
Correct me if I'm wrong or just way off track, but doesn't the current orange laser use two diodes?

Is it possible, to collimate two or even more diodes into a single beam? :-? You know, like having two engines in your car! ;D
Click to expand...

You are correct. It's a mix of 532nm and 650nm to make 593.5. It should be possible, with the right optics, to combine two beams into a single one without too much trouble.
 
In that case, what if you were to collimate a single beam from two 500mW diodes? I know it wouldn't be like series, more like parallel, so I wouldn't imagine the overall mW to double or even combine, I don't know. :-? But if you had two powerful lasers burning at the same spot, wouldn't they "assist" each other and burn twice as fast? Maybe combining two diodes do nothing for power gain, maybe only creating extra heat. Maybe the purpose of combining two diodes are benificial only for color, (nm) and do nothing for power (mW). Or maybe a twin diode laser could be used to create insane power!
 
You're both way off track here I believe. :P
Current yellow lasers are DPSS, they only have one IR 808nm diode and 2 crystals.Just like blue and green.Though the process is a little different, it's not combining beams and doesn't use 2 diodes.
A green + red combined beam is still 532nm and 650nm , it's not 593.5nm (our eyes see it as yellow because they don't have enough resolution to distinguish them) ::), and is nowhere near the quality of a DPSS 593.5nm laser.

About the other issue, yes ,combining two 500mW beams is going to give you a 1W beam if you do it right.You're gonna have less coherence though, but essentialy: two 500mW lasers shining on the same spot is going to be equal in burning with a 1W laser as long as they're the same wavelength so the absrobtion ratio is the same for each(same total energy transfered).
 
Switch said:
You're both way off track here I believe. :P
Current yellow lasers are DPSS, they only have one IR 808nm diode and 2 crystals.Just like blue and green.Though the process is a little different, it's not combining beams and doesn't use 2 diodes.
A green + red combined beam is still 532nm and 650nm , it's not 593.5nm (our eyes see it as yellow because they don't have enough resolution to distinguish them) ::), and is nowhere near the quality of a DPSS 593.5nm laser.

About the other issue, yes ,combining two 500mW beams is going to give you a 1W beam if you do it right.You're gonna have less coherence though, but essentialy: two 500mW lasers shining on the same spot is going to be equal in burning with a 1W laser as long as they're the same wavelength so the absrobtion ratio is the same for each(same total energy transfered).
Click to expand...

Orange, not yellow. There is a difference, right? Like blue and blu-ray. :-/
 
I think y'all should remember why peltiers are used in lab modules in the first place. They aren't there for cooling, they are there for active temperature regulation. With DPSS you don't want it to just be cold, ideally the diode and each of the crystals will each be regulated to maintain a certain temperature. At the very least though, you want to regulate the diode temperature. This way you get decent efficiency. Just keeping the diode at the right temp can mean the diff between 1W output, and 100mW output (or no output at all if you just try cooling it).

As for heat pipes and heatsinks and TECs and all that? Sounds to me like you might as well just take a lab module and hook up a battery power source to it and call it portable. To me, portability kinda ends once you reach the size of the Hercules - even that one is pushing the borders. I have a 200mW argon-ion gas laser that's technically portable. You close the top and there's a handle on it to carry it to the field (for forensics work). A nice 50 lb thing to lug around. So I guess a 1W greenie portable is readily possible... depending on how you define portability ;)
 
Ace/Amnizu, you're correct on two different things but you're getting them mixed up :D. 593.5nm DPSS and a yellow beam for lasershows are two different things.

RGY yellow made from combining red and green (IE a 532nm DPSS and 660nm diode) is not a set wavelength, just as there is no wavelength for white light. Its not monochromatic. They're not even one laser beam really. Its just a trick of the eye that when you overlap green and red light in the right combination, it takes on a yellow hue.

Don't confuse this though with 593.5nm which is a pure wavelength. Its a more pure color than you could ever get by combining red and green, and its a single monochromatic beam. To produce 593.5nm, you commonly use a single 808nm diode, Nd:YAG, and KTP - as Switch said, just like a green or a blue. The process is a bit trickier than making green or blue though ;)
 
Some people/companies call them orange, some call them yellow.....it's still 593.5nm though.I haven't seen a comercially available 532nm+650nm pointer yet :P
 
i think it was discussed in another thread, but what if i would like to create a white laser?
do i have to combine red, green & blue?
 
nikokapo said:
i think it was discussed in another thread, but what if i would like to create a white laser?
do i have to combine red, green & blue?
Click to expand...

Pretty much...some say blu-ray works too,some even tried , but the result is less than what you would expect.
 
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