Laserwave 1 watt OEM V-S

[bridge]

0-45 surrouding should be no problems, even write 10-35 degree using, design will left some room for terrible surrouding using, temp even can little lower, some customer here using in outdoors in winter, but we not advise.

But how many people want to pay for military spec laser shows?!

yes, that's true.

[sbk]

You also won't face cold time won't power normal, as the diode is bring heat and the OEM-V-S is without fan, the heat will make the TEC working it not very very low temprature.

And what if you stop the green laser output for more than 30 seconds? The crystal will cool down and when you start the laser again, you end up with 1/3 of the power until it reach a correct operation temperature, which take long time.

But how many people want to pay for military spec laser shows?!

Lasers don't even respect commercial grade temperature range (0-70°C). But anybody who want to do outdoor shows just *need* a green laser which remains stable at lower temperatures. Not really hard to understand, once you experienced it a few times...

[edison]

Although i never used the OEM-V-S its still a dpss laser and when it real cold the crystal needs to be heated. Many people suggested this and all european greens like RGBlasersystems, kvant , coherent etc have a heat and cool driver. It makes sence since in every enviroment (cold or hot ) the lasercrystal always is the same temperture. I,m the last person on earth that would question their engineerings skills. Even CNI have started with Heat and cool drivers. But maybe the OEM-V-S is a different design and it has less problems in cold weather. To be honest i like the laserwave drivers more then the CNI because of the bulky powersupply since the CNI needs 6v and 10v. The guy who designed that driver needs to have an education in industry standards

About blue and red the reds actually like cold surroundings since then they give even more power , planters can tell you all about that The blue needs tec but if its cold the tec doesn,t need to work that hard to keep it stable at the right temperture. For a dpss its different because when the crystal is cold the output is less instead of more.

But i,m interested to give them a try and see how they are. I have read some good things about them and Planters knows his stuff

[planters]

And what if you stop the green laser output for more than 30 seconds? The crystal will cool down and when you start the laser again, you end up with 1/3 of the power until it reach a correct operation temperature, which take long time.

No, not exactly. The crystal temperature management usually runs the temperature something above RT. And unless the outside temperature is so low that the heater cannot cope then the "warm up" period is to bring the bulk of the crystal and the mass of it's mounting to operational temperature. From that point on the modulation of the laser will cause the central core of the crystal (where the fundamental and the SH pass through it) to fluctuate and this will happen in even the highest grade lasers. This is simply an unavoidable consequence of the crystal's absorption. If the laser is "off" for 30 seconds the temperature control circuit will maintain the temperature near optimal, but will have just a little less heat load to deal with.

Regarding Edison's statement. I constructed a high end DPSS laser that has a biphasic Wavelength Electronics temperature controller, however with the KTP running @ approx 28C I have yet to see the circuit act in cooling mode. Of course, this is in a lab and maybe in a VERY hot club this could become an issue?

[andy_con]

I do happen to agree with whats been said, heating and cooling is a must for DPSS green modules and I would love to see this added to Chinese units

[The_Doctor]

Question... (as in, not assertion, this is just something I've wondered about a few times..)

A heat/cool driver is more complex, and crystals don't need a lot of energy to change their temperature compared to the diode. But suppose a bit of waste heat were a fair price to pay for ease and effectiveness? Could it work if you put a small resistor beside the crystal, with a constant current to heat it, then use a stronger TEC to cool only? It seems to me that the result is a higher 'torque' in the temperature regulation, so a better resistance to the effects of different heating by laser power. Also, the TEC control circuit could be much cheaper and simpler as it only has to cool to balance the resistor's heat. Put it another way: If you're going to provide heating, why not do it with the simplest component capable of it? As you're looking for balance, only the heater OR the cooler, seems to need control relative to the other which is fixed.

So the question is: if that scheme is useless, why?

[edison]

Regarding Edison's statement. I constructed a high end DPSS laser that has a biphasic Wavelength Electronics temperature controller, however with the KTP running @ approx 28C I have yet to see the circuit act in cooling mode. Of course, this is in a lab and maybe in a VERY hot club this could become an issue?

Its not the hot club that gives the issues with the DPSS. Its when it is below 10 degrees in country,s like Russia, norway, denmark, sweden, sibiria, finland, alaska, canada and all others on the nothern hemispere. When its cold the dpss crystal never reaches his ideal temperture and so it gives problems with modulation, stabillity in power output etc. A lab enviremont doesn,t show this but ask any laserist that is doing outside shows and they would say the same thing. But commercially a 1 watt dpps doesn,t need the heat and cool driver since 1 watt green is a little low outside. If you would do an heat and cool driver with a dpss i would suggest start with 2 watt and more heavy power modules. 1 watt is a little low for outside shows so commercially not real interesting to ad an more expencive driver. But i also think that when doing drivers in big quantaties like laserwave and others do it hardly cost more. It might be even cheaper to do all modules with 1 driver , since it saves stock parts and costs.

[carlos3621]

fwiw,
ive had modulation problems, on the last 3 , CNI oem modules i recently purchased,
and no issues with the last oem Laserwave module i picked up recently.

but both brands did have a nice tight low divergence beams.

[bridge]

Hi Edison,
Just like your blue and red, because itselves bring heat, it no need heat only need cooling.
Maybe you will say crystal need heat, but you will see our OEM-V-S LD and Crystal on the same base, you can consider it as one heat source.
Not like you used our lasers before ,it is our II type(black type with fan), which LD and Crystal depart and each using one TEC for cooling. also our before II type, even in winter, the fan still working, which make the heat disffuse and the crystal is working not at it's setting temperature. that's why Mr M0f said make the fan not working and the laser can working normal.
Also as I had said before, in very very low surrouding, just like -20degree, -30 degree, before you heat normal working, maybe you sudden power on will broken the crystal, so as I know, here who make outdoor using projector, they will using heat system make the projector inside surrouding temperature match normal laser using, I thought that 's the best way, which is also not expensive, maybe only a Resistance rods can make your projector match very cold places using, .
Best regards!
Bridge

[planters]

Doctor,

I think your idea is sound and that is one way to avoid two direction heating and cooling. There is something to think about when we are considering this as a problem for pretty low temperatures. All of the components of the projector have a temperature dependence. Just because the red and blue modules produce more power (they become more efficient and to a lesser extent require a higher voltage drop) this isn't without a down side; the color balance will certainly shift. The aluminum base plate will shrink and if the components are asymmetric then there will be some misalignment. And, certainly if a cold projector is brought inside condensation will form everywhere.

So, I like your idea, but I would kill about a dozen birds with one stone and provide the entire projector with a resistance heater, say thermal epoxied to the base plate and controlled with a simple uni directional relay control. This is the one I am using to drive the TECs that, in my case, cool the large diode pump modules in my DPSS. They are cheap and easy to use.

http://www.ebay.com/itm/DC-12V-Digit...item56570a9e3a