It looks like you’re finally starting to get sumwatt more serious about this little project.
:laughing: 
M9 is an unusual size. Never heard of it before now. Good to see more components rolling in. Hopefully the driver can be sorted out.
Yup, closed room, goggles, fire extinguisher at the ready.
M9x0.5 is odd but found on almost all security camera/fpv camera lenses and laser lenses, it seems to be the standard for those things that need fine adjustability of optics.
I want a good cooler that would be standard for all my testing, for better repeatability
The NH D15 is basically the best cooler that won’t be a liquid cooler.
Yikes! This is scary 
those youtube videos does not tell you how many hours you got before the diode degrades rapidly
you overdrive the diode already and any commercial module for laser show
serious quality laser engraver has TEC cooling or does drive the diode at lower currents within specs
The 6W opt lasers engravers only have an aluminum heatsink and fan cooling it.
I’ve seen people get up to 8+ W by cooling the laser in the fridge.
I don’t think I’ll be going anywhere near that high, maybe 6-7W at most assuming the crystal doesn’t burn up at that power.
My cooling should be significantly better than what opt lasers has on their engravers anyway
A little 
I’ve done a lot of research on lasers in the past but never owned a diode this powerful.
Safety first!
This cat’s observations about safety dated or not sure made an impression upon me.
I think he’s not over-hysterical about laser safety across the board per se butt where he does gets serious I do believe he’s SERIOUS. :laughing:
http://www.repairfaq.org/sam/lasersaf.htm#saftoc
http://www.repairfaq.org/sam/lasersam.htm
http://www.repairfaq.org/sam/laserfaq.htm
And some third-party harrowing stories of laser mayhem…… :person_facepalming:
https://www.photonics.com/Articles/Laser_Safety_Little_Mistakes_with_Big/a25167
Remember, it’s up to 20x as powerful as it seems to the eye (because it’s blue).
Those goggles are OD7+ so theoretically they should reduce the 6W of laser down to 0.0000006W (.00006mW) which is safe.
That is of course assuming the laser doesn’t stay on the goggles for very long or it will burn a hole through.
Yes, OD7 is quite strong. This topic becomes interesting when you take into account that a laser can be focussed using an optic…
In the above links I posted this Sam Goldwasser sez that laser glasses/goggles which are too restrictive are actually dangerous becuz ya can’t readily see at times where the beam is projecting, ending, etc. So the propensity is to do a quick sneak peek. That’s when apparently some of these eye injuries have occurred even from people who really know better.
It appears the more powerful the laser the proper goggle fitting process encompasses some touchy fine print.
Hey I’m just glad Endy isn’t gonna invite me over to sing ‘Candelas in the Wind’ while he fires up the scary sukkah. :person_facepalming:
I do everything in a closed room so as long as my eyes are safe it should be ok.
If the beam is concentrated I can still clearly see where it is, and if it spreads out past the focal point it ends up being low density and not capable of starting fires.
Fires and blindness are the main two safety concerns
JMO, butt I didn’t like it much when it was said to me “theoretically” when it came to things that can jack me up as they handed it off to me to try out. Ya know, bang, bang things. :cowboy_hat_face:
Ok understand. Now I’m curious though about sumthing. How do you absolutely KNOW that this particular pair of glasses will protect your eyes under the power levels only you really control? I assume the supplier sez that this particular diode at this particular top power range requires this minimum level of eye protection - and presumably you believe them. Or not?
However I surmise that you may exceed that range, maybe? And if so how do you determine watt glasses covers even inadvertent mistakes?
Ok. Enuff what ifs.
PS. Fires, blindness, and loss of love life. Hmmmmm. I’m not sure this is the right sequence of priorities for me. :laughing: :+1:
They are eagle pair glasses which according to my research over on the laser forums are a top brand.
Based on that I would trust the OD7 rating is true.
If you search up the OD scale you will find that level 7 is a 10 million reduction, which brings my 7W 450nm laser down to less than 1 microwatt.
That’s a lot less than the 1-5 milliwatt laser pointers that aren’t dangerous to eyesight.
I think you need to be in the tens or hundreds of milliwatts to cause damage.
I want to try messing around with my own LEP. I am new to lasers. I have many questions maybe I could get some help with? (should I make a new post?)
The “through hole” method seems more easier to DIY compared to the “reflecting method” that the Acebeam W30 uses. I am leaning towards the “through hole” method, but am concerned with the cooling problems the crystal may have. I am not trying to set any records. I just want a decent LEP that is better than the W30, so ease of build is more important.
- It is said to avoid back reflection. But will the lens used to focus the laser pose any potential problems?
- If I am using “through hole” how thick should my crystal be to be most effective?
- Is the NUBM44 a good choice even if I only use like 1W or less? Could I power it at like 1mw to just run tests and focusing?
- What optics should I use to have very good focus? I want my optics to be reliable so I dont have to worry about another factor.
- Could I technically buy a standard “laser engraving” module and just use it? Is there some special extra optics that a LEP needs?
- Based on my drawing of the “through hole” method, I have a collar and a beam dump and seems quite simple to DIY. Any foreseeable problems with my drawing?
- I am quite concerned with safety so I added a beam dump, are there other possible problems?
Price is not a concern for any components especially if it increase my chances of success.
1) if you get a proper laser lens it will be fine
2) no idea, the research papers only talk about lumens, not about intensity, so there really is no information on that yet.
3) I don’t think you can power it low enough to get only 1mW.
4) some professional grade plano aspheric lens, but that would be very expensive. Thorlabs has a 100mm one for about $1.5k
5) those 1W+ laser engravers are usually using a nubm44 and laser focusing lens.
6) drawing looks about right, except if you’re using a crystal then it will likely be only a few mm in size so you need a pretty precise mount.
7) you need to calculate the diameter of the laser beam at the lens based on the divergence, since the laser lens will focus at the phosphor and spread out afterwards in a cone. Your mirror or laser sink will probably need to be much larger.
Thanks for sharing your thoughts.
- Regarding mounting the crystal, what ideas do you have?
- Is it fragile like LED phosphors or something like a pcb?
- Is there some kind of glue I could use?
- What do you think the industry uses to mount these crystals? Even if it is mounted on a flat surface, how would it even be done?
- I will be purchasing some crystals from crytur.cz too. Would you still stick with crytur.cz if you had the choice of something else now that you have it? What about the 3x3mm size?
An idea I thought of is to glue the crystal to a piece of thin glass.
W30 is mounted on aluminium. I would mount it on a piece of silver. Then mount the silver on a copper water block. Thinking about building one.