Laser Hacks

657 Articles

Step Into My Particle Accelerator

December 11, 2025 by 14 Comments

If you get a chance to visit a computer history museum and see some of the very old computers, you’ll think they took up a full room. But if you ask, you’ll often find that the power supply was in another room and the cooling system was in yet another. So when you get a computer that fit on, say, a large desk and maybe have a few tape drives all together in a normal-sized office, people thought of it as “small.” We’re seeing a similar evolution in particle accelerators, which, a new startup company says, can be room-sized according to a post by [Charles Q. Choi] over at IEEE Spectrum.

Usually, when you think of a particle accelerator, you think of a giant housing like the 3.2-kilometer-long SLAC accelerator. That’s because these machines use magnets to accelerate the particles, and just like a car needs a certain distance to get to a particular speed, you have to have room for the particle to accelerate to the desired velocity.

A relatively new technique, though, doesn’t use magnets. Instead, very powerful (but very short) laser pulses create plasma from gas. The plasma oscillates in the wake of the laser, accelerating electrons to relativistic speeds. These so-called wakefield accelerators can, in theory, produce very high-energy electrons and don’t need much space to do it.

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King Tut, with less resolution than he's had since Deluxe Paint

Volumetric Display With Lasers And Bubbly Glass

December 10, 2025 by 21 Comments

There’s a type of dust-collector that’s been popular since the 1990s, where a cube of acrylic or glass is laser-etched in a three-dimensional pattern. Some people call them bubblegrams. While it could be argued that bubblegrams are a sort of 3D display, they’re more like a photograph than a TV. [Ancient] had the brainwave that since these objects work by scattering light, he could use them as a proper 3D video display by controlling the light scattered from an appropriately-designed bubblegram.

Appropriately designed, in this case, means a point cloud, which is not exactly exciting to look at on its own. It’s when [Ancient] adds the colour laser scanning projector that things get exciting. Well, after some very careful alignment. We imagine if this was to go on to become more than a demonstrator some sort of machine-vision auto-aligning would be desirable, but [Ancient] is able to conquer three-dimensional keystoning manually for this demonstration. Considering he is, in effect, projection-mapping onto the tiny bubbles in the crystal, that’s impressive work. Check out the video embedded below.

With only around 38,000 points, the resolution isn’t exactly high-def, but it is enough for a very impressive proof-of-concept. It’s also not nearly as creepy as the Selectric-inspired mouth-ball that was the last [Ancient] project we featured. It’s also a lot less likely to take your fingers off than the POV-based volumetric display [Ancient] was playing DOOM on a while back.

For the record, this one runs the same DOOM port, too– it’s using the same basic code as [Ancient]’s other displays, which you can find on GitHub under an MIT license.

Thanks to [Hari Wiguna] for the tip.

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[Usagi Electric] brandishing his raygun

Barcodes, “Lasers”, And Fourier Transforms

November 24, 2025 by 14 Comments

The Bomem DA3 is a type of Fourier transform spectrometer used for measuring various spectral data and [Usagi Electric] has one. On his quest to understand it he runs down a number of rabbit holes, including learning about various barcode formats, doing a teardown of the Telxon LS-201 barcode scanner, and exploring how lasers work. That’s right: lasers!

His reason for looking at the Telxon LS-201 barcode scanner is that it has the same type of helium-neon laser as his Bomem DA3 uses. Since he’s learning about barcode scanners he thinks it’s prudent to learn about barcode formats too, and he has a discussion with our very own Adam Fabio about such things, including the UPC-A standard barcodes.

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A photo of the transmitter and receiver.

Teardown Of HP Optical Link And Signal Investigations Using Siglent Technology

November 8, 2025 by 2 Comments

Anything with a laser has undeniable hacker appeal, even if the laser’s task is as pedestrian as sending data over a fiber optic cable. [Shahriar] from [The Signal Path] must agree, and you can watch as he tears down and investigates a fiber optic link made from old HP equipment in the video below.

He starts with an investigation of the block diagram of the transmitter. In the transmitter, the indium gallium arsenide phosphide laser diode emits light with a 1310-nanometer wavelength. Thermal characteristics in the transmitter are important, so there is thermal control circuitry. He notes that this system only works using amplitude modulation; phase modulation would require more expensive parts. Then it’s time to look at the receiver’s block diagram. Some optics direct the light signal to a PIN diode, which receives the signal and interfaces with biasing and amplifying circuitry.

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Is This The Last PCB You’ll Ever Buy?

November 2, 2025 by 44 Comments

Breadboards are great, but as the world moves more and more to having SMD as a standard, prototyping straight PCBs is becoming more common. If you’re mailing off to China for your PCBs, it’s shockingly quick for what it is, but a one-week turnaround is not “rapid prototyping”. [Stephen Hawes] has been on a quest on his YouTube channel for the ideal rapid-prototyping PCB solution, and he thinks he’s finally got it.

Now, if you’re only doing single-layer PCBs, this is a solved problem. You can mechanically mill, or laser cut, or chemically etch your way to PCB perfection, far faster than the Chinese fabs can get you a part. If you want a double-sided board, however, vias are both a pain in the keister to do yourself, and a rate-limiting step.

[Stephen Hawes] hit on the idea of buying a bulk set of PCBs from the usual vendors. The boards will be simple copper pours with vias in a grid with just a bit of etching. PCB Vendors are good at that, after all, and it’s not going to cost much more than raw copper. [Stephen] then uses the template of this “viagrid” board to lay out the circuit he’s prototyping, and it’s off to the races. Continue reading “Is This The Last PCB You’ll Ever Buy?” →

A frame from the two billion frames per second camera

Filming At The Speed Of Light, About One Foot Per Nanosecond

October 19, 2025 by 27 Comments

[Brian Haidet] published on his AlphaPhoenix channel a laser beam recorded at 2 billion frames per second. Well, sort of. The catch? It’s only a one pixel by one pixel video, but he repeats it over and over to build up the full rendering. It’s a fascinating experiment and a delightful result.

For this project [Brian] went back to the drawing board and rebuilt his entire apparatus from scratch. You see in December last year he had already made a video camera that ran at 1,000,000,000 fps. This time around, in order to hit 2,000,000,000 fps at significantly improved resolution, [Brian] updated the motors, the hardware, the oscilloscope, the signalling, the recording software, and the processing software. Basically, everything.

One of the coolest effects to come out of this new setup is how light appears to travel noticeably faster when coming towards the camera than when moving away from it. It’s an artifact of the setup: laser beams that reflect off of fog particles closer to the camera arrive sooner than ones that bounce back from further away. Or, put another way, it’s special relativity visualized in an experiment in [Brian]’s garage. Pretty cool.

If you found all this intriguing and would like to know more, there’s some bonus material that goes into much more depth.

An array of tiny parallel green lines appears over a steel surface. The white dot a laser beam is visible in the lower center of the picture.

A New Way To Make (Almost) Holograms With Lasers

October 17, 2025 by 6 Comments

The spectrum of laser technologies available to hackers has gradually widened from basic gas lasers through CO2 tubes, diode lasers, and now fiber lasers. One of the newer entries is the MOPA laser, which combines a laser diode with a fiber-based light amplifier. The diode’s pulse length and repetition rate are easy to control, while the fiber amplifier gives it enough power to do interesting things – including, as [Ben Krasnow] found, etch hologram-like diffraction gratings onto stainless steel.

Stainless steel works because it forms a thin oxide layer when heated, with a thickness determined by the temperature it reaches. The oxide layer creates thin-film interference with incoming light, letting the laser mark parts of a steel sheet with different colors by varying the intensity of heating. [Ben] wrote a script to etch color images onto steel using this method, and noticed in one experiment that one area seemed to produce diffraction patterns. More experimentation revealed that the laser could consistently make diffraction gratings out of parallel patterns of oxide lines. Surprisingly, the oxide layer seemed to grow mostly down into the metal, instead of up from the surface.

The pitch of the grating is perpendicular to the direction of the etched lines, and varying the line spacing changes the angle of diffraction, which should in theory be enough control to print a hologram with the laser. [Ben]’s first experiment in this general direction was to create a script that turned black-and-white photographs into shimmering matrices of diffraction-grating pixels, in which each pixel’s grating orientation was determined by its brightness. To add a parallax depth effect, [Ben] spread out images into a gradient in a diffraction grating, so that it produced different images at different angles. The images were somewhat limited by the minimum size required for the grating pixels, but the effect was quite noticeable.

Unfortunately, since the oxide layers grow down into the metal, [Ben] doubts whether the laser can etch molds for diffraction-grating chocolate. If you’re interested in more diffraction optics, check out these custom diffraction lenses or the workings of normal holograms.