Laserworld

[Jem]

... it measured ~500mw at FLEM with Adams coherent pen.

You just need to be aware that if there's any infrared in the beam at all it will skew the readings from the Lasercheck pen. You can minimise this by measuring the beam at a distance from the laser head as IR diverges fairly quickly (I think ).

I used to think LW lasers had IR filters fitted, but apparently they don't, or at least not all of them do

Cheers

Jem

[stanwax]

Jem

Laser-wave (like all the Chinese manufacturers) dont have a filter per-se but the output optics are HR coared for ir wavelengths. I beleive the reason with the higher powered modules at least (and I am ready to be corrected on this) is that the ir filter would be absorbing a large amount of energy which can lead to cracking/ destruction of the said filter (just like has happend in that blue you showed me recently ). The coating does not eliminate ir but reduces it significantly to a level thats almost negligable. The problem as you point out is that the LC goes bonkers when it gets any light of a different wavelength to what its set to.
As an example - I took some readings on an LW 500mW 532 laser that read 900mW on the LC with the beam straight on the sensor. Placing a GBR Laser-Wave dichro in the beam bounces the green and lets the ir through (the significant part of it). Then with the LC still set to 532 I measured the 2 beams - the bright green at 600mW and the little faint green dot (not all the green is bounced) that passed through measured almost the full 300mW that was missing. Close enough to sum to the right ball park. Nobody would ever be in doubt that the faint green spot was not even 1mW let alone a whopping 300mW!
Using a paper target and a ccd camera the ir blob was clear to see beyond the dichro.
So there was only one thing left to do - set the LC to measure the ir. The ir output will be a composite of 808nm pump light and 1064nm un-doubled lasing. Because of the pump beam focusing optics the pump light at the output will be very divergent, much being lost inside the housing, and though will affect the reading I treated it as negligable. So I set the LC to 1064nm and measured. I got a reding of around 20mW which even with some error is a bloody damn sight less than the 300mW previously seen. I dont know enough about the lasing within the cavity to know the sort of 1064nm power one should expect between the mirrors but it will sure be a damn sight more than the 20mW!!! I hope then this indicates that the actual ir level is not significant AND if you bounce your DPSS off any dichro that passes red most of this ir light will pass the dichro, be lost inside yor projector housing and never make it near the scanners let alone the output appeture.
Carl B uses this effect in his projectors by using the exact same dicho I test with as a bounce mirror for his green beams. He can rest assured that there is hardly any ir in his output - certainly no harmful level.
The lasercheck is a handy thing but far from perfect
Rob

[Jem]

Thanks Rob for the expert clarification

All I know is to be very careful when interpreting readings from the LC when measuring DPSS lasers.

Thanks again for the great explanation and method of overcoming the LC's weakness by using a dichro.

Cheers

Jem

[mophead]

UmmmHmmm. I See.

I have a power meter on the way here in a few days. I'll dig into this a little deeper then. I assumed given the quality of LaserWave products, unfiltered IR would be minimal if any. Makes sense though.

[stanwax]

like I say it accounts for a small percentage of the output - its just the LC cannot differentiate

Rob

[mixedgas]

prisms and gratings do wonders for ditching IR.'


Steve

[White-Light]

You've got me wondering again if mines really making stated figures now. It was overpower but again it was measured with an Coherent LC from a few centimetres off the diode. Perhaps we should have used a bounce mirror 1st.

[Jem]

You've got me wondering again if mines really making stated figures now. It was overpower but again it was measured with an Coherent LC from a few centimetres off the diode. Perhaps we should have used a bounce mirror 1st.

Red Diode lasers (within the visible spectrum ) don't produce IR

[Carl B]

Carl B uses this effect in his projectors by using the exact same dicho I test with as a bounce mirror for his green beams. He can rest assured that there is hardly any ir in his output - certainly no harmful level.
The lasercheck is a handy thing but far from perfect
Rob

And as I said to Rob on the phone last night I will be doing the same with the laser harp (undergoing a rebuild) as I don't want IR within the vertical beams that will be less than 2ft in front of me. I am confident that this is a good way to eliminate IR.

Carl

[dave]

The blue laser pictured in the tests.. The highest power CNI sell in that style, is 100mw

With a IR filter in, these lasers typically measure about 130-140mw.. Have you checked to see a IR filter is installed, as I doubt this is the case.. I doubt it is the case with the green either.. Well either that, or the power has been tweaked, which brings me to the red

Also, the red - AFAIK, the largest power CNI do in that style is 800mw. One we sold a while ago was doing 1w, so I think there is a little cause for concern there...

It might be worth testing with another power meter to rule that out...

UPDATE-

LaserWorld decided to send the customers new, "Proper" laser modules.
It took about a year, and this forum and negative post to get the "PROPER" Lasers which the customer paid for.

System #1- 2 WATT 532nm. Typical output stated: ~1.2W (i STILL dont like that way of stating powr outputs, but whatever.

Original output from factory- ~350mW. (Purchased as a 2W CNI.) Module was a refurbished "LaserCentury" or something module in there. please see original post for pics.

NEW LASER SHIPPED TO CUSTOMER AFTER HOUNDING THE HELL OUT OF LASERWORLD:

A Proper CNI Laser now!!!
Attachment 6639
And outputting what it SHOULD BE outputting!!!
Attachment 6640

System #2: 3.5 WATT RGB. Typical output- 2.3 WATT.

Original readings- RED 340mW
GREEN 130mW
BLUE 118mW
APPROX TOTAL- 600mW at White. (Supposed to be 2.3W minimum. 3.5 Typical)

RATED Specs-
RED- 1.7W @650nm
GREEN- 350mW @532nm
BLUE- 200mW @473nm

NEW MEASURED SPECS AFTER NEW REPLACEMENT LASERS SENT:

Red Laser:
Attachment 6641
Attachment 6642

>2 WATTS

Green Laser:
Attachment 6643
Attachment 6644

>500mW

Blue Laser:
Attachment 6645
Attachment 6646

240mW

NOW we have a pretty nice RGB laser going! still doesnt come close to their "typical output" specification of 3.5 WATTS. But at least it hits their minimum.

LaserWorld- WHY COULDNT YOU JUST DO THIS FROM THE BEGINING!?!?!? This is the SAME meter i used for the first tests. So, NOW YOU SEE....NO meter problems! and i DO know how to meter a beam of light!!!

Its good to see that you "made good" with this customer! i am VERY happy for these gentlemen that although its about a year later, they have FINALLY got the equipment they invested in.

Contrary to what you belive LaserWorld...i was and am NOT "out to get you" or ANY company for that matter!! You DO however, have some SERIOUS rethinking of your business model and ethical practices to go over. This is just ONE customer that has been cheated by you. You made good with THESE customers. but that DOES NOT excuse your poor business practices.

I am happy with the outcome from THIS situation. Although i know there are MANY other less fortunate people out there who invested ALOT of money into pretty much nothing!

And LaserWorld...please...for the LOVE OF GOD....NEVER LET PETER SPEAK ON YOUR BEHALF!!!!!!!! he has escalated this with his irresponsible and idiotic responses of jibberish!

i *HOPE* you change your ways LaserWorld!! i honestly do!!

-Marc
-CT. Lasers