eBay Nd:YVO4 + MgO:PPLN module.

[logsquared]

Well, After what looked like a promising start things went to sh!t real fast

My first attempt was simply setting the chip on an small aluminum piece. Aiming about 1-1.2 watts 808 at it and easily getting 250mW out. My power supply maxed at two amps. Before upping the juice I wanted to make a mount for the chip to put some pressure on it for heat removal. This is where I think I went all wrong. I put real light pressure on the clamp screws but I think it was enough to throw the cavity out of whack. After trying again with the chip in the mount I got more of a vertical line than a round dot. then moving the 808 spot around the face of the YVO4 produced some higher power but the output was mode hopping like crazy. After a while I couldn't get but a few mW out The crap thing is the seller upped the price to $200 from $125. I may try again with a more thought out clamping system or thermal epoxy.

Here is a pic of my death clamp.


Looking at it close up.... stupid F'in idea! Should have made it more of a vise clamping from top to bottom. Idiot.

[mixedgas]

ANY pressure on PPLN will kill the crystal. If you try again, try light clamping with a Indium spacer.

Steve

[logsquared]

Damn! Would i be better of glueing it with low out gas thermal epoxy? The bottom of the chip is mirror finish silicon and the top cap is copper. The data from the manufacturer says the crystals are attached to the silicon subcarrier (don't know how) with a copper cap.

[mixedgas]

Damn! Would i be better of glueing it with low out gas thermal epoxy? The bottom of the chip is mirror finish silicon and the top cap is copper. The data from the manufacturer says the crystals are attached to the silicon subcarrier (don't know how) with a copper cap.

Lets see, we have Indium, Conductive Epoxy, Artic Silver, Diamond Epoxy, etc...

Gotta get that heat out,,,

I need more pics...

Steve

[shrad]

you should have machined a depression on the mount and put the assembly into it with a small indium foil, and gently put a plate over it with nylon screws and another indium foil between the plate and the crystal, I guess

[VDX]

... I'm fixing or clamping brittle/sensitive devices mostly with 'leaf springs' - made some from spring steel, others from carbon compound or POM-sheets (sometimes with milled flex-joints) ... depends on optional heat transfer and/or supporting with current through the blades ...

Viktor

[logsquared]

Thanks for the input. I was thinking about what Steve said about pressure on the MgO. If I understand correctly its the polling in the crystal that makes the conversion. I would imagine the slightest twist or compression could distort the "layering" in the crystal. I know the base of my mount was very flat. So, my clamps must have put uneven pressure on the copper smashing or twisting it in some way.

I have come up with an idea for a mount that puts even pressure across the entire top. I am scared that any pressure might be too much seeing how soft copper is. And, how little pressure I put on the screws. I sent an email to the seller asking how they clamped it in there experiments. Hopefully they reply.

Right now I am leaning towards epoxy. I figure can epoxy the silicon side to a base then put the thermistor on the copper cap.

Anyone see anything wrong with the epoxy idea? I have some arctic silver epoxy. Not sure if is suitable though? Don't want any vapors to coat the end faces or my 808 emitter.

[VDX]

... common 2K-epoxies shouldn't exhaust vapours - I'm using "Uhu Endfest" for optics and silicone microsensors without need to clean then again after curing.

Another option are UV-curing epoxies - found "Bondic" in our tool-store - it's a small bottle of UV-resin and a 405nm-LED as hardener. It was around 20€ for 5g ... have a similar UV-resin for 3D-printing with a price of maybe 80€ per kg, so 50x cheaper!

Viktor

[logsquared]

What do you mean "2K-epoxies"?

Here is a close up of the MgO side of the chip. Looks like some epoxy filler around the crystal??

[VDX]

... "2K" stands for "2 components epoxies" - a synonym for autocuring epoxis consisting of two components that starts hardening, when mixed together.

The other types are "1K" - here it cures with light, moisture, heat or another external stimulus ...

Viktor