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Where can I purchase a 470 nm diode?

C

cybrian

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I've been asked to find these for a project for a customer of mine, and he's looking for something around 5-20 mW and exactly 470 nm. Any idea where I can purchase something like this? It'd be best if I can buy them in bulk quantities, too.
 





I'd try talking directly to Nichia for a bare diode -- expect to pay four digits (yes.) for the bare diode.

CNI does not even produce one, not even for $10,000. They do 447 in diode module, and 457 and 473 in DPSS.

Are you sure your customer cannot do 473nm vs 470nm? Because those extra 3nm and the willingness to go DPSS vs raw diode - is going to save him literally orders of magnitude of expense.
 
470nm can be very difficult to achieve even from a "470nm" diode. Most diodes are not exactly as rated. For instance, most of the "405nm" diodes I've worked with, are actually lasing at 408nm according to my Universities' calibrated spectrometer. The best way that I can think of, to get 470nm would be to start with a 473nm system that you would heat or cool until a wavelength shift happens. This is very tricky however, since it would require you to have a monitored and controlled TEC. Not to mention that DPSS systems can be very finicky about temperature.

If you have the time/money to do it, try it. But as far as something that only money can buy you, there is not much available.
 
Doesn't work that way with DPSS, meatball. You'll get 473, or nothing at all. wavelength shifts due to temperature only work with diode lasers. Since most of us run our blu-rays pretty hot, they shift a nm or three higher.

Yes, this is 5 figures if you need precisely 470nm. If you can settle for 473, it can be 3 figures.
 
Cyparagon - I got a DX 100mW BR pen that seems to be a hell of a lot more visible than all of my other BRs that are about the same power... I've heard of "High nm BR diodes" that are "natively" around 415; could that be the case?

I'm hoping to at some point get a ~415nm build from Igor.. I know he was having some supply troubles for a while.
 
aryntha said:
Cyparagon - I got a DX 100mW BR pen that seems to be a hell of a lot more visible than all of my other BRs that are about the same power... I've heard of "High nm BR diodes" that are "natively" around 415; could that be the case?

I'm hoping to at some point get a ~415nm build from Igor.. I know he was having some supply troubles for a while.
Click to expand...

Likely higher wavelength, and very well could be over 410, but you'd have to put it on a spectrometer to see for sure. When it's right on the edge of visible, just a couple of nanometers can make a huge difference in visibility.

There was a thread in General somewhere about old-school spectrometer with a viewing thing and a diffraction grating for cheap...or find a lab or school that has a spectrometer. That's literally a 30 second measurement.

But yeah, the wavelength tolerances are pretty high, and you can get multiple nm higher out of a laser diode from a temperature increase alone. Especially compared to DPSS, in which wavelength is set by a physical constant of the system, diode wavelengths can very quite a bit from one production run to another and even within the same wafer.

----------------------------------------

And for the OP, yeah, you're not going to get exactly 470nm out of a laser without major expenditures. You'd have to contact a manufacturer directly and get a custom-made diode, not even just an engineering sample, because the tolerances even on production diodes are generally +/-5nm. It'll have to be custom-made for you, and then you'll have to have some good temperature control and other things like that to make sure there's no drift, especially if you want to go near CW operation.

And diodes aren't that spectrally pure anyway. What is the application that needs exactly 470nm and won't allow for 473 nm? (which is much more commonly available).
 
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Cyparagon said:
Doesn't work that way with DPSS, meatball. You'll get 473, or nothing at all. wavelength shifts due to temperature only work with diode lasers. Since most of us run our blu-rays pretty hot, they shift a nm or three higher.

Yes, this is 5 figures if you need precisely 470nm. If you can settle for 473, it can be 3 figures.
Click to expand...

Thats interesting...

I'm pretty sure I've seen most 532 modules with a +/-10nm tolerance listed with the output wavelength. I wonder why that is...

:undecided:
 
Meatball said:
Thats interesting...

I'm pretty sure I've seen most 532 modules with a +/-10nm tolerance listed with the output wavelength. I wonder why that is...

:undecided:
Click to expand...

That's a CYA rating. It's people putting the same tolerance on all their diodes and modules in order to cover their ass for all circumstances and all lasers, while not knowing any better when it comes to lasers. The 532nm comes from doubling the 1064 emission line of Nd dopants in a crystal matrix. Since the emission is coming from the dopant atoms, the emission wavelengths are determined by the atomic orbitals of the individual dopant atoms, which are constant.

To contrast, laser diode emission is determined by bands (formed by bringing the orbitals of many atoms close together) instead of by individual orbitals. Since electrons/holes can move around in energy within bands (they have an allowed range of energies instead of the discrete energy levels around individual atoms), the average energies of the electrons and holes change with temperature, and therefore the transition energy for releasing light can change with temperature.

Make sense?
 
pullbangdead said:
That's a CYA rating. It's people putting the same tolerance on all their diodes and modules in order to cover their ass for all circumstances and all lasers, while not knowing any better when it comes to lasers. The 532nm comes from doubling the 1064 emission line of Nd dopants in a crystal matrix. Since the emission is coming from the dopant atoms, the emission wavelengths are determined by the atomic orbitals of the individual dopant atoms, which are constant.

To contrast, laser diode emission is determined by bands (formed by bringing the orbitals of many atoms close together) instead of by individual orbitals. Since electrons/holes can move around in energy within bands (they have an allowed range of energies instead of the discrete energy levels around individual atoms), the average energies of the electrons and holes change with temperature, and therefore the transition energy for releasing light can change with temperature.

Make sense?
Click to expand...

Makes sense. So then DPSS is much higher in tolerance because emission comes from the MATERIALS doped in the matrix, and diodes are lower in tolerance because emission comes from between the BONDS of materials used. These bonds can vary the energy bands with temperature? Diode emission has a little bit of a wider emission band since the energy bands can vary by a tiny amount.. correct? I bet that's a quantum mechanics thing I haven't gotten to yet.

Thanks pullbangdead.

-Tyler
 
Yeah, that WOULD be cool if there was a store where you could buy a DIODE for ANY wavelength laser that you wanted to build. rob
 
DPSS wavelengths are from atomic transitions and cannot be modified at all. There is no possible way to shift a 532 to 522 or 542, but the -/+ 10nm tolerance claim is still valid and easily met (1 nm is met too).

Diode lasers on the other hand can be switched in wavelength by varying temperature. This shift is in the order of 0.3 nm per degree kelvin. This makes shifting wavelength by a few nm entirely feasible using TEC or heating.

You wont be able to shift a 450 nm diode to 470 though - that would take a 60 degree rise in temperature, which is likely to kill it or result in very inefficient operation. If you can obtain something 468 or 472 at room temp, you could tune it to 470 spot on thermally if you wanted to.
 
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