Picture of DPSS 808 & 532nm !

There is one picture showing dpss but i didn't remenber who take it, this picture lies somewhere in the forum :



Here is my contribution of diode pumped solid state laser. Picture are not photoshoped (just resized), taken with a panasonic fz28 +water fog to reveal the beams (you can notice some water in the picture), it take me some hours to obtain these result, im particular happy to have captured these shots !






















You can download (30MB) high res picture pack (10MP) Here. :wave:

Very cool pictures! One interesting thing you can clearly see here is that the green and nIR laser beams are not collinear, but have a slight angle between them. Do you know whether that's inherent in the frequency doubling process or just because the crystal edges aren't perpendicular to the beam (i.e. diffraction)?

^That's due to diffraction, although the beam pointing stability can at times be affected by the internal conditions of the crystal. Depending on these conditions (temperature, transverse mode structure, etc) the refractive properties of the gain medium can change.

Incredible pics, Maus! I'm surprised that your results weren't affected by the condensation..

These are amazing, I've never seen these little fellows like that.

When is the 473nm version coming out ?

Aha, the first one is mine I cant even remember what thread that was from..

I'm a noob to lasers and am trying to research how to build a 532nm through LPF. I am beginning to look through the DIY pages but will probably never actually build one. Please help me understand this correctly, an 808nm laser shined through certain crystals will yield 532nm? Does the mW output greatly decrease after passing through the crystal? What lenses and mirrors are needed to increase the power? Is building a laser always more expensive than buying one? Does anyone else know of any other good threads I should check out? Thanks.

You need to read this. It will give you a very good description of what is happening here.

One interesting thing you can clearly see here is that the green and nIR laser beams are not collinear, but have a slight angle between them.

Click to expand...

Exact ! some of the 808nm not absorbed by the crystal pass through him and we obtain 2 spot of remaining 808nm which are visible, and 532 nm. But is it diffraction or refraction ? i must investigate the inner working of single harmonic generation

the 808 nm pump is a Heruur 9mm at 830mA, crystal set come from common greenie;
picture were taken when the output of 532 nm was oscillating (not stable sometime).
I had huge difficulty to increase the distance between the lens (plastic aixiz) after the pump, and the position of the crystal set : the more far the point of focalisation (by moving the lens to the pump) the less is the output of green, i don't understand why, because the point of focalisation at greater distance was much better than in close position.

It could be refraction as well. As long as all your IR is being focused into the Nd:YVO4 portion of that DPM at an agle perpendicular to the vanadate face, there shouldn't be a significant amount of IR leakage apart from the green output (there should not be enough collimated IR remaining that you get two diffracted beams). The OC coating on the KTP is HR@1064, and the OC coating on the vanadate is HR@808nm. Between the two coatings, they should stop nearly all IR.

Personally, I think that what is being seen here is a result of the incident pump energy coming in at a slight angle instead of perpendicular to the vanadate face.. most likely this slight angle is causing refraction as the photons change mediums.

I've collimated 808nm to pin head about 1cm away from the aperature with a second collimating lens(very high divergence) before passing it through a crystal set and the resulting green had a divergence no greater then that shown in these pics by mauswiesel. Light conversion is a very interesting event

Ideally the waist at the focal point of the pump diode output should be positioned just inside the vanadate crystal rather that being focused directly on the face. This allows for maximum pump absorption by the vanadate which improves the overall efficiency. The final beam divergence is determined by the cavity length rather than the divergence of the incident pump energy.