Laser-wave to CNI Compare Test

[Phritzler]

Hello CNI Laser!
I don´t say that your lasers are much bad or shit or something, I only say that laser-wave is better... For example I can also say jenlas is better, but this are labour lasers. So don´t feel angry about this.
The problem of the most chinese manufractorys is to hold the Quality! For example: My green CNI put out 3cm beam, I must adjust outputlens for get 1.3cm beam, other CNI put out 1.3cm beam or 8mm beam after 10m.
This is only one small example ...
Thanks,
Phil

[CNI LASER]

In my experience CNI laser outperform their spec sheets, meaning that the specs are on the safe side (as they should be). In 2003/2004 I had very different experiences with other manufacturers. The fact that CNI publishes realistic specs (not the best but realistic) was one of the reasons I bought from them (end 2006).

However, the spec sheets still do not tell the whole story. We are also in interested in:
1) linearity of the modulation
2) duty cycle dependency - very important for color balance - view (you might want to play it a few times to see what is going on)

These are typically expected to be 1) linear and 2) non existing by customers, since they need to be for our laser show application. Can laser manufacturers take that expectation seriously and build their lasers so that these properties are within acceptable limits (= not visible during laser shows without concession) as a default quality standard?
Can they publish these specs, preferably as charts?

3) more info on the blue speckles problem. CNI states "noise of amplitude ~ 30%" for 473nm lasers. This must be the speckles problem and CNI is openly telling the world it is there, which is great! The number doesn't really tell me how severe it looks though - well after buying I know. Can CNI bring this number down to, say 10%? Will it cost extra?

These are the issues I came across, there are probably more so others can append the list.

best,
Matthijs

Hi

30% amplitudinal rms noise :is the short time stability in us,and it's no relate to the speckle.For lasershow appication,amplitudinal isn't important.
For industrial use,we can do 3% amplitudinal rms noise.

[Phritzler]

Hello Guys.
I broke the test now.
Thanks for your help and tests,and point´s what to do.
Phil

[Zoof]

Hi

30% amplitudinal rms noise :is the short time stability in us,and it's no relate to the speckle.For lasershow appication,amplitudinal isn't important.
For industrial use,we can do 3% amplitudinal rms noise.

OK, thanks for explaining. Is CNI getting the speckles problem under control for their blue lasers?

[CNI LASER]

OK, thanks for explaining. Is CNI getting the speckles problem under control for their blue lasers?

For 473nm 1-250mW 473,we can do perfect one good beam.As for the higher power,they are on developing now.

Sorry.

[CNI LASER]

I know CNI's product are not perfect by now,and we are all CNI colleague are trying to improve the quality all the time.It's ok to do the compare of laserwave with CNI or other manufacture in China with us.Even all these words were right,please don't use only this to cover all the good lasers from CNI.

Anyway,thanks a lot for all the good comments from you all.We'll try to solve all the problems.

[bridge]

Hello Guys.
I broke the test now.

I don't know what happen, I am really a little disappoint, but I am sure compare will never stop, all of us are looking for better prices with cheaper unit for ever. so fair compare will never stop.
thanks phill for his harding working, long time test,he try his best to do this. anyway, till now, after about 1500hours, both lasers are not lose much.

CNI 400mW and Laserwave 412mW.

The CNI is gone to exact 352mW, and the Laserwave only lost 15mW! So it has 395mW exactly...

before we expect 5000hours even 8000hours long test, but now we only got about 1500hours test information, what a pity.
thanks for all of you attention and join.
wish another compare later. maybe blue is best, as blue is the most problem one, .
Best regards!
Bridge

[CNI LASER]

I don't know what happen, I am really a little disappoint, but I am sure compare will never stop, all of us are looking for better prices with cheaper unit for ever. so fair compare will never stop.
thanks phill for his harding working, long time test,he try his best to do this. anyway, till now, after about 1500hours, both lasers are not lose much.


before we expect 5000hours even 8000hours long test, but now we only got about 1500hours test information, what a pity.
thanks for all of you attention and join.
wish another compare later. maybe blue is best, as blue is the most problem one, .
Best regards!
Bridge

It's absolute ok to do the compare long test 5000 or 8000hours.Who laugh last isn't determined.I hope you can produce more new lasers to compare with CNI's.It's also good for us.It's let us step up more quickly.Thanks.

It's not a bad thing for us.

[Zoof]

Such that we can develop an intelligent list of spec's to ask for when ordering.
I think what may be happening is we are providing too little information to our suppliers. This opens the door for them to send whatever complies with our "lack of detail"... beware the ignorant so to speak.

<snip>

All of these from well known manufacturers.
These issues can be summed up as poor final quality checks and controls.

Hi Ray,
so what we need is a "Photon Lexicon Quality Score Sheet" that communicates the desired quality standard to the manufacturers and tells them how important it is for us that the laser falls within spec. This score sheet should somehow be used in the final quality check to communicate to the customer how well the laser scores prior to sending it out.

What do the manufacturers think of this?

By the way have you looked at what it takes to send back a laser unit to China for repair.

Yep, its an awkward process involving a lot of patience and a bit of praying

cheers,
Z.

[buffo]

With my own lasers I have had.
Mod hopping.
Fatter green beam than I thought I was getting.
Blue laser with a little crescent artifact.
Poor assembly of power supply causing cutting in / out
Supply of a second hand laser head of unknown origin instead of new.

See... Now this is the sort of thing that bugs me about Chinese laser suppliers. There is *no* excuse for a laser with artifacts, or one that mode hops, or one with a faulty power supply. This isn't a matter of "defining the proper specs"... This is a FAILURE TO TEST YOUR PRODUCT before you ship it to your customers.

It is *never* acceptable to ship a laser with the defects listed above. But all too often a Chinese supplier will claim that "We could have fixed that if you had asked..." WRONG! The customer shouldn't have to ask for basic quality.

They know once you get it there is little chance you will send it halfway around the world back to them to fix due freight and customs issues. !!

You are absolutely right, Ray. I've spent over $150 in shipping fees alone over the past year just to send my Lasever DPSS blue laser back to China 3 times. Lots of people don't realize that a warranty isn't all that great when you have to pay to send it back. (Fortunately I've been lucky on the customs issue. Never had a product siezed. But I've always labeled it "defective power supply - return to manufacturer".)

30% amplitudinal rms noise :is the short time stability in us,and it's no relate to the speckle.For lasershow appication,amplitudinal isn't important.

Amplitudinal noise *is* important to lasershow applications! This is the heart of the so-called "jellybeaning" problem. The power output is *not* consistent when you operate the laser on a variable duty cycle. Saying that it isn't important tells me that you aren't paying attention to what the laserists here have been saying.

For industrial use,we can do 3% amplitudinal rms noise.

*ALL* your lasers should meet this spec, not just the ones for industrial use!

Ray's idea of a spec sheet is a good one, but really it shoudn't be required. As a laser manufacturer, I would hope that CNI understands some basic requirements like linear power response on an analog-blanking laser, no blanking-induced power loss (jellybeaning), low divergence beams, no beam artifacts, and stable TEM00 operation. These are common-sense specs.

If a laser manufacturer can't deliver on these basic requirements, then their lasers are unfit for laser show use - period.

One spec that I *do* believe should be explicitly defined is the blanking speed. As Bill Benner pointed out a long time ago, there is no real spec for blanking speed, especially among Chinese manufacturers. Some lasers say they support 10 Khz blanking, while others claim 15Khz, 20Khz, or more. What, EXACTLY, do they mean by this? No one really knows.

I propose that if you are going to spec your laser as supporting a given blanking speed specified in Hz or Khz, then that means the following:

1) The blanking signal is assumed to be a square wave signal with a 50% duty cycle. (That is, the laser is only on for 50% of the time.)

2) The power of the laser reaches 90% of full power (or 90% of whatever power level is selected, in the case of an analog blanking unit where the blanking signal is somewhere in the middle of the range) within the length of a single blanking pulse when the blanking signal goes high. (For a 10Khz blanking laser, this would mean the laser reaches 90% of full power in 50 microseconds or less.)

3) The power of the laser falls to zero within the same time period (or faster) as in # 2 above when the blanking signal goes low.

4) During operation, blanking the laser at any speed or duty cycle up to it's rated maximum (in Khz) will not adversely affect the beam quality. (This means no mode hopping, no artifacts, no noise, and no power fluctuations greater than 10%.)

This is a pretty basic standard. It is in no way ideal, but it's a start. (An ideal standard would have the laser reaching 97% of it's rated power within the duration of the blanking pulse, and would use a 10% duty cycle to more accurately demonstrate any jellybeaning.)

My point is that if *I* can come up with a basic performance standard like this, why in the hell can't the manufacturer do it? They're in the BUSINESS of making lasers, yet they don't even know how to test them to see if they're working correctly? (Surely laser show applications aren't so arcane that the laser manufacturers don't know what the basic requirements are...?)

Adam