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How much power are you all losing through your scanner dichros and mirrors? I'm only getting around 1/2 of what my laser put out. I could stand to clean my mirrors but I don't know how much good that will do.
I think my galvo mirrors are to blame for most of it. The only other mirrors I have are the red and blue dichros that I got from Edmunds Optics and they should be pretty good.
First make sure that you are not measuring and IR light coming from your green or blue.
Second, meter before dichros, after dichros, and after galvos... Post your results here, I would like to see them.
1/2 to losses would be a fairly inefficient system.
Also what galvos are you using?
-Max
I have massive losses on the DT40pro galvos. IIRC I lose about 40%:eek:
Jim
I have the DT40pros and I haven't seen that much in losses :-/
I will check again when I get my projector back together.
Sounds about like my galvo mirrors. That annoys me because the specs I received for the galvos said the reflectivity was >95%.
Quote:
Originally Posted by JimBo
i have original dt40's (not pro's) i have replaced both mirrors, i got the replacement from Jian.
i will do some testing soon
I loose between 4% and 5% across each mirror, for a total loss of between 8 and 9% across the scanner pair. The losses are about equal on both my original DT-40's and my newer DT-40 pro's, and are comparable with the losses I've measured on other galvos I've reviewed.
If you're loosing 40% across your scanners, something is seriously wrong.
Adam
i lose about 100mw at 3 watts argon. (give or take) but have not burned them yet! they seem to pass the light and lose the heat.
About 10% tops across all dic mirrors and golvos. Check your galvos and make sure you install them right. Coating is on one side so make sure this side is the one reflecting.!
Yeah the way to make sure that you are reflecting off the front surface of the front surface mirror is to hold something up to the mirror. If the reflection touches the object then that is the correct side. If the reflection is a little bit distant then that is the bad side. I use something like a needle, and I touch to a part of the mirror close to the shaft where the laser will never hit.
Hey Carm... here's the 'skinny': (with complimentary 'spellcheck' fixes!) :D
Quote:
Originally Posted by Buffo
Quote:
Originally Posted by mliptack
IF, after re-checking with these fine suggestions, you think that your galvo mirrors ARE bad - try sending a beam directly thru one of the galvo mirrors at 0 deg. incidence-angle (straight on) and see- VISIBLY (not metered)- if you get any significant (>5 mW out-of 100mW) 'pass-thru', - then repeat, with the galvo mirror at 45 deg. (careful with reflections! ‹(•¿x)› doh!) ;) and if you are seeing a LOT of pass-thru (like say 30mW out-of 100mW), well, time to ask for replacement mirrors...Quote:
Originally Posted by Dr Laser
Also, try test again, MEASURING results reflecting OFF galvo mirror - ie: say coming out of laser X, you directly-measure 100mW (or whatever your powers are) of green, but off galvo-mirror bounce-tests, it is 40mW (and there is NOT 60mW of green VISIBLY-passing thru the galvo mirror out into the room - especially at 45 deg.), well, then time to discuss 'rated power @ Xnm' vs what you are measuring off those bounces, with the people that sold you the DPSS... :D
IF after these tests, you feel that the galvo mirrors ARE truly bad, AND your galvo manufacturer does not/can not help you (out of warranty, don't sell replacement mirs, etc), check with Fred or Amanda at One Stop Laser Shop (PL member "OSLS") - they have many types of galvo-replacement mirrors, and if your shafts can take a 1mm-thick mirror, they sell the best aerospace-grade broadband dielectric mirror we've ever used...:cool:
Hope this helps! :)... peace.
- J
Thanks for all of the tips. I'm going to try some different things as I have time.
Make sure your dichros are all at 45 degree angles to the beams also... ;)
ok done a few tests with my green and blue dichro from edmund and my dt40 which have brand new mirrors on them.
im loosing hardly anything, a few mw.
but something i noticed my green pointer is producing 37mw and im loosing 17mw passing through the blue dichro. this seems a little high to me?
the green looses only a few mw when passing the red dichro.
also with the new mirrors im only loosing a few mw on the galvo's, nothing major
so all in all good results for me
Could it be that your measuring some IR leakage that the galvo mirrors don't reflect?
its a new wicked pointer, so should have an ir filter
yes keyword SHOULD :eek: