Laser Power Output Losses?

[Systematic]

Hi Guys,

This is my first post on here, hope you are all well. I know this is a great site for information, I've read a fair bit on here already.

I have a question with regards to power losses using Pangolin Quickshow and an FB3. I have read that you are going to get losses which is fine but I am still confused by the power readings I am getting from my meter.

I have an RGB laser which I am measuring the beams with a Coherent Laser Check whilst using Pangolin Quickshow.

The powers sent to me by the manufacture with pictures before any software was used were:

Red - 637nm= 580mw
Green - 532nm = 728mw
Blue - 445nm = 961mw

Total power = 2,269mw

Powers after using Quickshow are:

Red = 574mw (1.03% loss)
Green = 513mw (29.53% loss)
Blue = 525mw (45.37% loss)

Total = 1,612mw (28.96% loss)

What is the usual loss from an FB3 as this seems rather high to me or is this normal?

I am measuring a CW beam using the beam target section setting the beam power to 100% and heating the laser up for half an hour prior to measuring each colour. I am unsure if I am doing this correctly. Is this the correct way to get a CW full power beam out of Quickshow?

It could be that my power meter is wrong as the Red is not getting as much of a loss.

I am based in south London and wondered if there is anybody based near me that would be able to help me with this maybe I could take my laser to your's or something if this is not a normal amount of loss?

Any help would be greatly appreciated.

Thank you.

[edison]

try contact Rob stanwax from greenlaser.co.uk He is a member here too. He probably can help you out. Your blue driver needs 5v input modulation signal to give maximum power output. I think the FB3 gives only about 4.4 and this can give problems. Rob can solve this easily for you and it is good to meet him as well i think. Give him a call or send him a pm that is your best bet

[dave]

LOL, last time I checked, all my FB3's output 5v!

I think you will find, you are not getting true measurements, because your lasers are being modulated...

[edison]

Wasn,t there a problem with impedance for a while? I assumed that everyone knows that you should have a solid 5v on the input of the drivers when doing measurements but yes when having it modulated then it will give a lower output.

Anyway you could send it to australia too but after a quick peek on the global map i think Rob is just a little bit closer to you

[Megatron]

Hi guys I'm very intrested to know how you get a non modulated beam out of quickshow? Can anyone help with this? Sorry cant help with the answer to this thread tho

[norty303]

You cannot get an unmodulated beam out of Quickshow due to the nature of how it works.
You need to connect a 5vdc source to the driver.
Rob Stanwax has a little unit that can do it easily I believe (although I'm making an assumption it can do a single beam rather than a test frame)
I use a DB25 connector with trailing wires soldered on, that I connect to a regulated 5v supply.

Wasn,t there a problem with impedance for a while

Isn't that a problem with the laser driver not meeting the ILDA spec, rather than the FB3?

Although it's been said ad infinitum, remember that you cannot measure DAC voltage with a meter (well, you can if you just want to know if voltage is present), but if you want to know how much, you need to use a scope.

[Megatron]

Ok cheers for your help Norty303 it's quite annoying that you can't get a non modulated beam out of quickshow but anyway if that's how it is never mind. I will have a look on Robs site for that device that you are talking about.
Cheers, Sam

[norty303]

Its this one.
http://shop.stanwaxlaser.co.uk/ilda-...tool-294-p.asp
Might be worth a PM to rob to see if the quadrature pattern can be disabled, although you could always just measure power pre-scanners/optics.

[gottaluvlasers]

1) What Laser manufacturer is the Laser projector?
2) What Lasers are *inside* of the projector?
3) Where are you measuring the beams power? AFTER all optics at aperture? or at the Laser head?

- If this system is of "lesser quality", i.e.- Chinese or Laserworld- then expect optical losses of AT LEAST ~30%.

4) Where did the manufacturer who sent you the specs measure their power readings?

You really should do what Norty said. Go buy a DB25 connector and just solder a few wires onto it and hook it up to a known clean 5V DC power source. This will ensure you have a SOLID, non-modulated signal going into your drivers.

-Marc

[dsli_jon]

Might be worth a PM to rob to see if the quadrature pattern can be disabled..

: Far-simpler to just 'cock the DB-25 (output-side) to one-side', thus de-coupling the X-Y pins, whilst deftfully-leaving the RGB-pins connected.. works the charm..

PS, to the OP: small, unsolicited plug for this product from Sir Rob - indispensable little piece of kit, worth every shilling And you can quite-easily pop one in a nice little 'outrigger box', with some toggle-switches, for easy-selection of 'scan-speeds' for the quad-pattern...

http://www.photonlexicon.com/forums/...0&d=1331295679

..in-all, a hearty three-cheers for it..
.02
j