WTB: KNbO3 crystal (or place to buy these)

just won an "940nm LASER DIODE 2W 9mm case" on ebay.
seller says that you can make a 470nm laser if you use a KNbO3 crystal.

but these seem hard to find. anyone know locations for buying these?
and is it true it will put out around 500mW 470nm ?

laserwinkel said:

just won an "940nm LASER DIODE 2W 9mm case" on ebay.
seller says that you can make a 470nm laser if you use a KNbO3 crystal.

but these seem hard to find. anyone know locations for buying these?
and is it true it will put out around 500mW 470nm ?

Click to expand...

That would be herurrsciences(also known as hesc_photonics on ebay) who is also a member on this site. Check the GB section for his sales tread, I recall seeing such a crystal. As for your question, I'm not sure if directly doubling 940nm is even possible. I know that KNbO3 can double 976nm diodes to get 488nm; even then, the diode and crystal must be near perfectly aligned and temperature controlled... This is by no means easy or cheap; it's doable but not on a hobbyist budget or equipment. Herur(Chris) tends to trivialize complicated processes such as direct doubling. Also, you will not get 500mW even if it worked; the efficiency of KNbO3 is atrocious...

Listen to digital_blue.

Direct doubling is difficult on the manufacturers level, damn near impossible on a hobby level.

Let me put it this way, if you get 5mw of 470nm, I will give you my blue rpl. Yes, it is that difficult. I believe laser_ban had a directly doubled laser in your wavelength range. It used a pump diode emitting 10s of watts for something in the area of 10s of mw's, it was manufactured by coherent (again IIRC), hope that sums up the difficulty of the process.

I am not trying to discourage you from making your own dpss laser, but even aligning YV04 and KTP nicely can be a large PIA and I suggest you start there.

laserwinkel - If you still want to continue with your project, your gonna need need an incredibly stable TEC module with a temperature controller(possibly with optical feedback). You will also need specialty optics for the laser cavity and a good diode to double. In the end, you may get a 20 or so mW; you gotta consider though, is it worth the effort and time? You're probably gonna have better luck building a 473nm than a directly doubled laser... My advice, use the diode for burning, don't bother with the KNbO3; You will end up wasting more money unless you have some DPSS experience...

Valuable advice in these replies. You guys are right on. Direct doubling a diode is very difficult. You probably could get some blue light out of that potassium niobate crystal, but the beam quality would be horrendous. To get any kind of usable output requires some serious engineering.

ok i'll just make this a burning laser then hehe
thanks for all the advices