Femtosecond Laser Clones Itself In Glass

October 3, 2023 by Maya Posch 4 Comments

When researchers at the Galatea laboratory in Switzerland set out to create a femtosecond laser in glass they weren’t certain it was going to work. To be precise, their goal was to create a femtosecond laser cavity using carefully aligned optics. Rather than using the traditional, discrete method, they used a commercial femtosecond laser to carve out the elements of the optical cavity in glass. The choice for glass came down to the low thermal expansion of this material, and it being transparent for the optical frequencies being targeted.

Generic concept of an “all-glass” optical device, with the various stages of fabrication. (Credit: Antoine Delgoffe et al., 2023)

Even after using the existing laser to create the rough laser cavity, the resulting optical mirrors were not aligned properly, but this was all part of the plan.

By also adding slots that created a flexure mechanism, brief laser pulses could be used to gradually adjust the mirrors to create the perfect alignment. During subsequent testing of the newly created laser cavity it was found to be operating as expected. The original femtosecond laser had successfully created a new femtosecond laser.

Perhaps the most tantalizing aspect of this research is that this could enable much faster and ultimately cheaper production of such laser systems, especially once the tedious and currently completely manual mirror alignment procedure is automated. In addition, it raises the prospect of producing other types of optics including splitters and guides in a similar manner.

Mosquito Laser Death Grid Is Just What It Sounds Like

September 22, 2023 by Lewin Day 37 Comments

Mosquitoes suck. Quite literally. [Allen Pan] lives in an area where they’re so thick in the air, regular methods of killing them fail to put a dent in their numbers. Thus, he set about building a solution so dangerous we wouldn’t want to be within a mile when it’s turned on.

[Allen] was inspired by a TED talk from over a decade ago that involved targeting flying mosquitoes with high-powered scanning lasers. This technology never really came to fruition, and raised many questions about laser safety and effectiveness.

Testing the idea with only two mirrors installed.

This solution keeps the lasers, but goes a slightly different route — two 10-watt lasers bounced between multiple mirrors to create a laser death grid. It goes without saying that 10 watt lasers will blind you near instantly even at great range, and can burn skin and cause all manner of other horrors. Bouncing them around with mirrors and waving them about at mosquitoes is a really poor idea when even incidental exposure can do real harm.

Indeed, the laser is so powerful that it burns holes in the mirrors [Allen] used in early testing. It was around this time that [styropyro] was brought in to help ensure everyone involved got through the project with their eyesight intact.

[Allen]’s crew wears laser safety goggles when operating the horrifying handheld device, which mitigates some risk. The team also quickly notice beams escaping from various directions, due in part to the holes burned in their clothes. Electing to wrap the device in a heatproof blanket to avoid accidentally dazzling any nearby pilots was an obvious idea but turning the device off and destroying it would have been smarter.

Sadly, despite looking like the coolest cyberpunk weapon we’ve seen in years, the device doesn’t even kill mosquitoes very effectively. The bugs largely avoided the device, and only a few that flew directly into a beam ended up being cooked. The whole time watching the video, we feared someone dropping the rig, leading to a 10-watt beam bouncing off and striking some poor innocent bystander.

Powerful lasers are cool and useful things. Try and use them responsibly.

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Cold Metal Fusion For 3D Printing

September 20, 2023 by Al Williams 13 Comments

When you see the term cold fusion, you probably think about energy generation, but the Cold Metal Fusion Alliance is an industry group all about 3D printing metal using Selective Laser Sintering (SLS) printers. The technology promoted by Headmade Materials typically involves using a mix of metal and plastic powder. The resulting part is tougher than you might expect, allowing you to perform mechanical operations on it before it is oven-sintered to remove the plastic.

The key appears to be the patented powder, where each metal particle has a thin polymer coating. The low temperature of the laser in the SLS machine melts the polymer, binding the metal particles together. After printing, a chemical debinding system prepares the part — which takes twelve hours. Then, you need another twelve hours in the oven to get the actual metal part.

You might wonder why we are interested in this. After all, SLS printers are unusual — but not unheard of — in home labs. But we were looking at the latest offerings from Nexa3D and realized that the lasers in their low-end machines are not far from the lasers we have in our shops today. The QLS230, for example, operates at 30 watts. There’s plenty of people reading this that have cutters in that range or beyond out in the garage or basement.

We aren’t sure what a hobby setup would look like for the debinding and the oven steps, but it can’t be that hard. Maybe it is time to look at homebrew SLS printers again. Of course, the powder isn’t cheap and is probably hard to replace. We saw a 20 kg tub of it for the low price of €5,000. On the other hand, that’s a lot of powder, and it looks like whatever doesn’t go into your part can be reused so the price isn’t as bad as it sounds. We’d love to see someone get some of this and try it with a hacked printer.

We have seen homebrew SLS printers. There’s also OpenSLS that, coincidentally, uses a laser cutter. It wouldn’t be cheap or easy, but being able to turn out metal parts in your garage would be quite the payoff. Be sure to keep us posted on your progress.

Tricks For Mass-Producing Laser-Etched Art

September 15, 2023 by Lewin Day 26 Comments

Art is a funny thing. Sometimes, it’s best done in a one-off fashion and sold for a hugely inflated price. Othertimes, it’s more accessible, and it becomes desirable to sell it in great quantity. [Wesley Treat] has been doing just that, and he’s shared some of his tricks of the trade on YouTube.

The video concerns some retro-futuristic raygun artwork panels that [Wesley] made in a recent video. The panels proved mighty popular, which meant he had a new problem to contend with: how to make them in quantity. His initial process largely involved making them in a one-off fashion, and that simply wouldn’t scale.

[Wesley] starts right at the beginning, demonstrating first how he produces stacks of blanks for his art panels. For production scale, he used pre-painted matte aluminium panels to speed the process. It’s followed by a sanding step, before the panels go into a laser etching jig to get imprinted with [Wesley’s] maker’s mark. Panels are then drilled via CNC, etched with their front artwork, and then fitted with a front acrylic panel, similarly cut out on the laser cutter. Then it’s just a matter of packing and shipping, a logistical hurdle that many small businesses have had to overcome.

[Wesley] does a great job of examining what it takes to scale from building one of something to many. It’s a topic we’ve looked at a few times in the past. Video after the break.

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An automatic laser turret playing with a cat.

Entertain Your Cats Automatically With LazerPaw

September 5, 2023 by Julian Scheffers 22 Comments

Most of us would agree that kittens are very cute, but require lots of attention in return. What would you do if you adopted three abandoned cats but didn’t have all day to play with them? [Hoani Bryson] solved his problem by building LazerPaw — an autonomous, safe way to let your cats chase lasers.

Having recently tinkered with computer vision in the form of OpenCV, [Hoani] decided he would make a laser turret for his cats to play with. An infrared camera, used so that the LazerPaw works in the dark, is mounted to the laser and the Raspberry Pi. These electronics are then mounted on a servo-based pan/tilt module, which is in turn mounted with two smartphone clamps to the ceiling. That way, when the cats chase the laser, they will be looking away from the beam source. Additionally, if the device is aiming directly at a cat, the laser is turned off. Finally, [Hoani] added some NeoPixels with an Arduino-based controller for extra hacker vibes.

The LazerPaw’s software takes in a 30 FPS stream from a webcam, scales it down for performance, and applies a threshold filter to it. When a black pixel, which is assumed to be a cat, is detected, it “pushes” the camera away from it depending on how close to the laser it is. The effect of this is that every time a cat catches up to the laser, it moves away again. The processed images are also sent to an interactive website for remote cat playtime. Finally, there is also a physical start button so you don’t need WiFi to use it.

Is your cat more of a sunbather than a deadly murder beast? Maybe it’ll like this cat chair that follows the sun.

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Review: WAINLUX K8, A Diode Laser That’s Ready To Work

August 28, 2023 by Tom Nardi 24 Comments

Rarely a week goes by that some company doesn’t offer to send us their latest and greatest laser. You know the type — couple of aluminum extrusions, Class 4 diode flopping around in the breeze, and no enclosure to speak of unless you count the cardboard box they shipped it in. In other words, an accident waiting to happen. Such gracious invitations get sent to the trash without a second thought.

Now don’t get me wrong, I have no doubt that the average Hackaday reader would be able to render such a contraption (relatively) safe for use around the shop. Build a box around it, bolt on a powerful enough fan to suck the smoke out through the window, and you’ve turned a liability into a legitimate tool. But the fact remains that we simply can’t put our stamp on something that is designed with such a blatant disregard for basic safety principles.

The earlier WAINLUX JL4 — lucky rabbit foot not included.

That being the case, a recent email from WAINLUX nearly met the same fate as all those other invitations. But even at a glance it was clear that this new machine they wanted to send out, the K8, was very different from others we’d seen. Different even from what the company themselves have put out to this point. This model was fully enclosed, had a built-in ventilation fan, an optional air filter “sidecar”, and yes, it would even turn off the laser if you opened the door while it was in operation. After reading through the promotional material they sent over, I had to admit, I was intrigued.

It seemed like I wasn’t the only one either; it was only a matter of days before the Kickstarter for the WAINLUX K8 rocketed to six figures. At the time of this writing, the total raised stands at just under $230,000 USD. There’s clearly a demand for this sort of desktop laser, the simplicity of using a diode over a laser tube is already appealing, but one that you could actually use in a home with kids or pets would be a game changer for many people.

But would the reality live up to the hype? I’ve spent the last couple of weeks putting a pre-production WAINLUX K8 through its paces, so let’s take a look and see if WAINLUX has a winner on their hands.

Continue reading “Review: WAINLUX K8, A Diode Laser That’s Ready To Work” →

This 3D Scanner Uses A Sensor You Might Not Know About

August 14, 2023 by Jenny List 24 Comments

The huge diversity of sensors and other hardware which our community now has access to seems comprehensive, but there remain many parts which have made little impact due to cost or scarcity. It’s one of these which [Enginoor] has taken for the sensor in a 3D scanner, an industrial laser displacement sensor.

This sensor measures distance, but it’s not one of the time-of-flight sensors we’re familiar with. Instead it’s similar to a photographic rangefinder, relying on the parallax angle as seen from a sensor a distance apart from the laser. They are extremely expensive due to their high-precision construction, but happily they can be found at a more affordable level second-hand from decommissioned machinery.

In this case the sensor is mounted on an X-Y gantry, and scans the part making individual point measurements. The sensor is interfaced to a Teensy, which in turn spits the data back to a PC for processing. By their own admission it’s not the most practical of builds, but for us that’s not the point. We hope that bringing these parts to the attention of our community might see them used in other ways.

We’ve featured huge numbers of 3D scanners over the years, including a look at how not to make one.