Review of 70 mw DPSS blue from Dragon Lasers

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Originally Posted by Dragonlasers.com

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The reviewed blue laser for instance had a tested power level in excess of 70mW. We would sell it as a 50mW. We would not sell it as a 70mW laser because that is not conservative enough. You can see from our price list that we sell 50mW not 70mW 473nm lasers. With the review laser in question, the price was $800-$850 for a 50mW laser tested at 70mW by us and independently at 75mW. The final half price of $400 for a 50mW laser was a special price because of all the work that was put into the review and for the convenience of tying up loose ends.

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The bottom line is you bought a 20mw laser from CNI and are selling it as a 50mw. In my book that is dishonest and you are a cheat!!
I am the one who is buying this laser from Adam and will honor my commitment to do so. But I will never buy another laser from you. I can not put this laser into one of my projectors and sell it as a 50mw no matter what the output. It is meant to be sold as a 20mw and labeled as such! If I tried what you are doing in the US I would be out of business fast or sued for fraud.
I don`t think you will sell many lasers here.

I like the idea that it came in way over spec for a 20mW unit....if it will continue to make this power some 8000 + hours into it's lifespan. I agree that if it says it is a 20mw unit it should be priced and sold accordingly , regardless of how far above spec it does. I dont have the say so to get into who , why or how the wool got pulled over the stinky side of things. I would be intrested in one if the truth was prevailing in all aspects..... As for my 473 unit.....it does what it's supposed to do. Spec'd at 200mW.......actually making 247mw@5v after 1 hr run time.

Well, this didn't turn out very well at all, did it?:(

For the record, after I declined to purchase this laser for the discounted price of $400 from Dragon Lasers, Fred mentioned that he was interested in it. Dragon Lasers didn't have a problem with Fred buying it at that same discounted price, so I sent the laser to him. (He hasn't received it yet.)

In light of the recent revelation that the laser is actually a "hot" laser that is really only spec'd for 20 mw, I called Fred and asked him if he'd like to back out of the deal. I feel responsible here, and I was willing to buy the laser back from him to make him whole.

However, Fred said that he still wanted the laser, though he was quite dissapointed at being misled. Let's hope that it continues to make the same 75 mw that it's making now for a long, long time. But if it drops in power after a year or two, I know I'll feel pretty guilty about it.

I'd like to point out that I'm not making any money on this; I just thought that a price of $400 for a 75 mw blue laser was a good deal, and if *I* wasn't going to take advantage of it (because of the TTL blanking and lower power output than the one I already have), it made sense for *someone* to get a deal. However, now that we know it's actually a 20 mw laser, it's not such a good deal anymore...

Fred was willing to take the risk even though he now knows what he's really buying. But if I had everything to do all over again, I would just send the laser back to Dragon Lasers at their expense like we had originally planned.

Thanks to everyone that pointed out the CNI sticker's power rating. (Dave, Aijii, Fluff, and I'm sure I'm missing a few others too...) Honestly, if you guys hadn't brought it to my attention, I would have simply shrugged it off as a mistake in packaging. I suppose I should be a little more skeptical in the future...

Adam

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Originally Posted by MechEng3

I like the idea that it came in way over spec for a 20mW unit....

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yes - why i pointed out it said very good things about the manufactuer. We consistently see above spec lasers coming from CNI, when we purchase directly.

Hey Adam,

I enjoyed your review and a lot of good has come out of this by way of info for all of us... (after all isnt that what a review is supposed to uncover) ..well done once again.
It seems that dealing with a foreign country can have some hidden barbs.
I have a situation which we are currently trying to resolve on one of my units. Don't want to go into any detail as yet on the laser as the final outcome is not known. Aijii is helping me resolve it with the manufacturer. All I will say at this time is sending expensive lasers back to China can have some hidden consequences in terms of customs duty or you must be prepared to outright lie about its value then maybe lose it altogether ??.
Anyway I digress... good reporting and info Adam keep up the good work.
Cheers
Ray
NZ

True. While we all need to watch for things, we're not all able to know what we see. Spotting that label and questioning it was enough. Showing detailed info was enough. Without more direct knowledge of the maker's methods of specification, there is no way to know for sure, so no blame can be laid on the buyer.

In this case the seller made what is a reasonable decision, but it's still not the best one. The best is to refer back to source, EVERY time. If a laser comes from CNI doing less than they claim, send it back. I imagine they'll sort it, as it sounds like it isn't happening often, and they won't be overworked fixing that. This way the reseller doesn't lose out, so there's no need to try to claim more money on the other lasers.

Edit: If buyers actually refer direct to source, CNI or whoever, then this problem will fall off dramatically. If CNI get a pattern of reports that implicates a specific reseller, they can refuse to sell to them on the grounds that they need to protect their reputation and retain a right to decide who they sell to. That way no-one needs to sue anyone, and no money gets wasted on lawyers, and the laser market improves. This mechanism is the only one I can think of that can easily and cheaply work across any international border, so it looks like the way to go.


More edit:
That raising of claim is reasonable as I said, but it's the maker who should do it, not a reseller. Only the maker is qualified to know for sure what increase in claim is viable (20 to 75 does suggest a LOT of true overhead for it), and only the maker can fix it if they get that wrong. If CNI did this it would reduce the margin of opportunity for resellers to try it.

Thanks for the vote of confidence, Ray. I appreciate it!

Dave and Aijii are good guys; hopefully they can help you resolve your problem.

As far as customs issues - yeah, that *is* a problem. I've run into that before. (My first laser was declared as a "sample of plastic material" when it arrived!) Like you, I'm uncomfortable lying on a customs form that could land me in legal trouble. I must admit though that I have "fudged" a little. I had a laser die on me a while back, and I needed to send it back to China to get it fixed. I was asked to declare it as "defective power supply - return to manufacturer". That was partly true, since at the time we thought the power supply was the cause of the failure. I figured that it would be enough to get me off the hook if the package was ever inspected, and fortunately customs accepted it without a fuss. But I was a tad bit concerned at the time, because there was a lot more in that box than just a power supply.!.

Anyway, the one good thing that did come out of this review is that I've proved to myself that CNI lasers really are all that and a bag of chips... I'll be sure to keep that in mind the next time I'm looking to buy.

Adam

This is all pretty interesting. I'm curious to know where the extra power is coming from. Is the current from the P/S too high or is the diode just more efficient? Is the case designed to dissipate the extra heat?

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Originally Posted by carmangary

This is all pretty interesting. I'm curious to know where the extra power is coming from. Is the current from the P/S too high or is the diode just more efficient? Is the case designed to dissipate the extra heat?

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The case and internals are made to satisfy the maximum drive power intended for a range of outputs. (Every LambdaPro UG has innards capable of handling the stresses that can drive 180 mW of green, even if only putting out 50 mW) The largest variety comes from the vanadate and doubling crystal. In most lasers in a range, the diode will be pumping whatever the maker determines as safe maximum for decent lifetime. (LambdaPro used half-power to do this, and whatever their vices, their pump diodes do seem to last). Some crystals will have a stable operation at high output and can be rated high, others might go high but only be stable at lower power, so that's how they'll be rated.

I imagine this can put a strain between a laser maker and their crystal supplier, if too many cases are built to good spec and too many crystals arrive that won't make good use of that.

I really don't know, carmangary... I think the laser head is robust enough that it could handle a little extra heat (the head assembly is massive), so even if the current was turned up a little bit it would probably handle it. (Don't know about the TEC though...)

Then again, the optical cavity might just be really well aligned. Or maybe the crystals are just super-efficient. Hard to say, really. But it's making 75 mw, and did so for well over 100 hours. Only question is, how long will it stay like that... ( I gotta admit that the head stayed cool during all the tests, including the burn in.)

Dave and Aijii have a lot of experience with CNI lasers, and they say that it's not uncommon to see one making a lot more than it's rated power, especially on the lower end of the spectrum. That might explain it. (CNI lasers are naturally "hot" when it comes to power...)

Adam