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FrozenGate by Avery

Red DPSS laser?

H

Hydrogen

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Mar 8, 2011
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As an idea, what would happen if when doubled a red diode, instead of IR, a normal red LD is 650nm so what would be the end result nm?

Through YV04 and KTP.
 





those crystals don't just work with any wavelength you throw at them.
They only do their magic with 808nm as input.
 
Sure they do, when you pump them with a 808nm diode....:rolleyes:
Otherwise: no they don't.
 
The critical factor in any solid state laser is the absorption spectrum of the crystal you are using. Nd:YVO4 (used in most low power DPSS lasers) has good absorption in a narrow range around 808nm. There are other absorption lines but 808nm works the best because you can pump a large volume of power into a crystal set with a relatively small laser diode. Pumping a Ti:Sapphire laser is done with 532nm lasers, as another example. In some cases the optimal absorption spectrum is not used simply because it can be very expensive to pump the crystal set. In other cases other absorption spectrums are used because they are better suited for the crystal set to lase at a minor lasing line. Rare earth doped glass, garnet and sapphire based crystals are very well understood and have been around since shortly after the first ruby laser fired. The holy grail of solid state laser physics is to find the next crystal dopant that lases as easily as the rare earths. There are some good books out there that can get you up to speed on solid state laser systems physics.
 
It's good to hear your pearls of wisdom again FC I haven't heard from you in a Long time ;)
 
Thanks you all for your reply, I noticed a little IR coming from my laser, I have put a camera IR cut filter over the aperture, it's better now.
 
One last idea, well more of an question, can I pot mod but my laser with extreme cooling, so it wont break?
 
if i've learned correctly. the crystals can only handle x amount of power from pump diode. so i will say now. you cant get an extreme amount of extra power from extreme cooling. you could possible take a 50mw greenie and pump it to be a 100mw. i have done this. and the laser lasted for years. but you still want to use a multi meter to see where your driver is at and where you adjust it too.
 
chipdouglas said:
if i've learned correctly. the crystals can only handle x amount of power from pump diode. so i will say now. you cant get an extreme amount of extra power from extreme cooling. you could possible take a 50mw greenie and pump it to be a 100mw. i have done this. and the laser lasted for years. but you still want to use a multi meter to see where your driver is at and where you adjust it too.
Click to expand...

At the moment I'm having LOADS of trouble trying to get the laser apart :(
 
Yes, there is a limit to the amount of power you can put through a crystal set. In a good resonator design the focal point of the pump diode in an end pumped configuration and the shape of the OC and HR mirrors creates a beam waist inside the crystal set. So in reality you never use the entire crystal set. At the focal point the energy density can be quite high and can result in fracture of the media (blitzing the rod, we used to say). Even cooling the rod is often not enough because the thermal variations across the length of the rod create physical stress to the crystalline structure. Because of this you can often see mode hopping and other artifacts when the rod is severely stressed. Short rods like in pointers and small lab systems fair much better. Furthermore, the non-linear process for SHG lasers is temperature dependent. Fortunately, Nd:YVO4 can take a pretty good beating versus say Nd:Glass.

Again I would recommend some reading on solid state lasers. We have a few books at the office that are good for those not so adept at advanced calculus such as: Fundamentals of Light Sources and Lasers by Mark Csele. He gives a good background in photonics and lasers using algebraic principles. He's also a laser hobbyist. His site is here: The Professor's Homebuilt Lasers Site
 
If you are wanting an 808nm IR laser (based on the video) I'll be sure to photograph and film the one I'm building at work. I'm not building it to have an IR laser. I'm building it because I need something that requires 5+ amps to test a new computer controlled driver system. It'll be a 5 watt system when I'm done. I'll add some cylindrical lenses to the mount so it burns nicely.
 
FrothyChimp said:
If you are wanting an 808nm IR laser (based on the video) I'll be sure to photograph and film the one I'm building at work. I'm not building it to have an IR laser. I'm building it because I need something that requires 5+ amps to test a new computer controlled driver system. It'll be a 5 watt system when I'm done. I'll add some cylindrical lenses to the mount so it burns nicely.
Click to expand...

You are awesome, can you also tell me why, I set the pot on MAX, and the bare IR diode collimated wont burn?

according to this, YouTube - Full Optical Mod of 5 mw Green Laser to IR Burning Laser " No Removal of Module Required " I have done it right, it should burn.

finally this works, but it wont burn anymore, I think I potmodded it too much, but it still gives off IR?
 
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And for some reason the green crystal wont turn the IR into green anymore, I think the IR has gone dim?
 
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