Fiber laser power problem

[TheHermit]

Planters has gone OTT & is asking for help on Tech Ingredients

[VDX]

... ich you "ignore" the fiberlaser and only use the power of the pumping diodes of this fiberlasers, bundled all together, then you'll get 3 times the average output power

[TheHermit]

... ich you "ignore" the fiberlaser and only use the power of the pumping diodes of this fiberlasers, bundled all together, then you'll get 3 times the average output power

I suggest that you watch the video.

Planters' problem is having more power than he can handle.

[VDX]

... you can't have "too much power" -- it's more the question, what's the best use for

[TheHermit]

... you can't have "too much power" -- it's more the question, what's the best use for

With respect VDX, it appears that you are unfamiliar with Eric Planters' long history of laser work and are underestimating his knowledge level.
Considering your personal experience of working with >1500W,
why don't you accept his challenge to provide a practical solution in his video's comments for safely terminating his beams (while they're tracking and shooting down flying drones, as he successfully demonstrated with lower power in a previous video), then he will credit you on camera and make you famous.
😎

[buffo]

if you "ignore" the fiberlaser and only use the power of the pumping diodes of this fiberlasers, bundled all together, then you'll get 3 times the average output power

True, at the expense of beam quality. Obviously the trade-off isn't worth it.

you can't have "too much power" -- it's more the question, what's the best use for

Well, he already has a great use for the power (destroying drones in flight), he just needs a way to continue testing the system indoors without setting fire to the building.

Admittedly, instead of calling this a problem of "too much power", you could re-phrase it as "we need a suitable backstop material that won't be too expensive" if you wanted.

But "too much power" makes for a better title for a YouTube video...

With respect VDX, it appears that you are unfamiliar with Eric Planters' long history of laser work and are underestimating his knowledge level.

Nah, I think he's just poking fun at Eric's choice of words for the title of his video.

For the record, Eric has attended SELEM in the past, and he used to post here on the forum quite a lot back in the day, so I'm sure Viktor remembers him even though it's been ages since we've seen a new post from Planters.

Regarding the actual issue raised in the video, Eric mentioned that he tested standard sheetrock (gypsum board) and found that it worked fairly well, so I'm surprised he didn't think to try backerboard (aka cement board). This is the stuff you use on a bathroom wall if you're going to put up tile. Since it's made from cement, it should be a lot more durable than regular sheetrock.

Another option I would have investigated would have been hardy-plank siding, as it also uses cement as a binder. Taking this idea to the extreme, it might even be possible to use pre-cast concrete slabs as wall segments, assuming you could get them thin enough that each segment could be lifted into place and mounted by hand.

Realistically though, unless you have access to the ceramic tiles they used on the space shuttle, anything you use for a backstop is going to suffer *some* damage from the beam of those fiber lasers. (Look at the damage done to the brick that he showed in the video!) The best you can hope for is to find something affordable and easy to replace that is also durable enough to withstand at least a few direct strikes in the same spot without burning through.

Adam

[VDX]

With respect VDX, it appears that you are unfamiliar with Eric Planters' long history of laser work and are underestimating his knowledge level.
Considering your personal experience of working with >1500W,
why don't you accept his challenge to provide a practical solution in his video's comments for safely terminating his beams (while they're tracking and shooting down flying drones, as he successfully demonstrated with lower power in a previous video), then he will credit you on camera and make you famous.
😎

... I'm pretty aware of his long history and contributions ... have had some discussions with him too, before the first Trump's election -- after then he "vanished" fron this forum

And I too was somehow involved in "shooting down" flying drones, as possible test-application for one of my (then not drone-related) day-job-projects, where I've developed a "tracking device" with the NVIDIA-AI-boards (Jetson Nano and Xavier NX), stereo-cam-pairs and IR-illumination and -filtering, to work at day and night and in dark areas ... meant to detect, track/target an eliminate mosquitos(!)

My own "direct diode"-lasers are actually only in the range of some hundred watts, as used to laser-weld and for additive manufactureing apps ... but have actually collected enough of the pumping diodes, as salvaged from multi-kW-fiberlasers, to combine something like some ten kilowatts CW power in a beam of some millimeters to centimeters diameter


And last -- for "shielding" materials I'm using normal bricks in an arrangement of up to 2 layers, meant to withstand some serious "melting" (then replace them, if too worn out) ... and eventually gas concrete (have manufacturer for both in the neighbouring towns) ... or sand ...

Viktor

[TheHermit]

-- after then he "vanished" fron this forum

Yes, I get the impression that there were some harsh words previously exchanged.
Eric's explanation is that he wanted to focus upon his YT channel to cover a broader range of subjects. However, he still often revisits various of laser builds.

... (Jetson Nano and Xavier NX), stereo-cam-pairs and IR-illumination and -filtering, to work at day and night and in dark areas ... meant to detect, track/target an eliminate mosquitos(!)

Had a play with the Jetson Nano & stereo cams, a few years ago, until it died. Great range of SBCs.
Now into Teensy, completing the final development phase of a humble midi controlled T4 Laser Synth abstract imaging system.
IR mosquito tracker/killer sounds like a great and worthy project.
Your creds are very impressive. Pleased to meet you.

And last -- for "shielding" materials I'm using normal bricks in an arrangement of up to 2 layers, meant to withstand some serious "melting" (then replace them, if too worn out) ... and eventually gas concrete (have manufacturer for both in the neighbouring towns) ... or sand ...
Viktor

Others have made similar suggestions, including ceramics. on Tech Ingredients' comments section.
I posted this thread, thinking that it would be of community interest and who better to solve Planters' problem than fellow laser folks?
Best regards,
Roj
😎

[TheHermit]

(Look at the damage done to the brick that he showed in the video!)

Adam

Yes and that's why I don't see Hardee Backerboard nor siding handling the heat , neither.
TBH, I don't see the need for such power against RC drones, unless for a DOD proof of concept patent and/or contract. He's already tracked and melted flying RC drones.
IHO, an alternative approach would be to reduce power, expand the beam near field, focus on the flying drone (~20 ft range within the shop) then terminate a larger beam of lower power density down range.
🤷*♂️

[VDX]

... killing drones by aiming lasers needs either a pretty sophisticated targeting/following methode, to hold the beam for up to some ten seconds on the same spot ... or enough power, to burn through the hull and interior in some milliseconds!

And, if someone want to "shield" the drone against this, its enough to coat it with mirrors along the sensitive areas

Viktor