A rectangular black box is shown, connected to a coil of fiber-optic wire. Out of the end of the fiber, purple light is emitted. A label in the lower right corner says "405nm Singlemode Light Source".

Building A Fiber-Coupled Laser Source For Precision Optics

June 30, 2026 by Aaron Beckendorf 4 Comments

Laser diodes are convenient light sources, but for precise optical work their often-elliptical beam profile leaves something to be desired. One way to get around this is to couple the beam into a single-mode optical fiber, which then emits a circular Gaussian beam from the other end. For more advanced experiments, therefore, [Diffraction Limited] built this fiber-coupled laser source.

The simplest approach is to place the fiber directly against a light source, but this results in most of the light missing the three-micron fiber core. Optical fibers have an acceptance cone, and only light approaching from within this cone is coupled into the fiber. The design therefore uses an aspheric lens to focus light from the laser diode down to a tiny point matching the diameter of the fiber core, creating a cone of incoming light narrower than the acceptance cone.

The body of the laser source was CNC machined out of brass, with the laser-diode press-fit in one end. The lens stands in front of the diode, and was glued in place so that its focal point was just above the end of a mounting pin for the glass fiber. Positioning and fixing the fiber in place was the biggest challenge; [Diffraction Limited] could use the micro-manipulator from a previous video to position the fiber, but the UV-set glue used to fix it in place shrinks during curing, pulling it out of position. To deal with this, two set screws under the mounting pin allowed its position to be adjusted slightly after gluing. As expected, adhesive shrinkage meant that the completed source initially produced no light, but after the set screws were adjusted, the beam appeared.

For more on fiber-coupled lasers, check out [Les Wright]’s work. If you don’t have access to an aspheric lens, an anti-bumping bead could be a reasonable alternative.

2026 Frikkin Lasers Challenge: Super-Simple Laser Precision For Your Stargazing

June 29, 2026 by Tyler August 11 Comments

Perhaps the hardest thing for amateur astronomers just starting out is finding the things you want to look at. Prolific maker [mircemk] has submitted a quick-and-easy star-hopper device that will help guide your binoculars with laser-like precision using things you likely already have on hand: a smartphone, a mounting plate, and a green laser pointer.

The smartphone is running AstroHopper, an astronomy app that uses GPS and inertial navigation to know exactly where your phone is pointing, and offer an image of the sky on the screen. There are many others of this ilk, and there’s no reason [mircemk]’s trick won’t work with your favorite. The trick is decidedly simple: the smartphone is mounted to a flat plate, in line with a green laser pointer. Careful placement aligns the axis of the phone and the laser, and the mounting plate is set up to fit a tripod.

Using it is simple: with a labelled view of the sky displayed on the screen, one lines up the phone/laser combo with the desired object, and activates the laser pointer. [micremk] has wired in an on-off switch for this purpose and a large external battery, rather than relying on the stock pushbutton. Since the axis of the laser pointer and the phone are aligned, a green line launches out into the heavens for you to follow with your binoculars. Once you locate that green dot, you can turn off the laser. Yes, the computer has helped you find the object, but your muscles are doing the slewing and that will make it much more likely you start to learn the sky yourself rather than relying on electronic magic.

This is probably the simplest hack we’ve yet seen in the Frikkin’ Lasers Challenge, and yet also one of the most practical. If you enjoy playing with radiation that’s spontaneously emitted, there’s still time to get your entry together — the contest runs until July 23, 2026.

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All The Different Lasers, And How Well They Mark 3D Prints

June 24, 2026 by Donald Papp 19 Comments

[Stefan] of CNC Kitchen has an informative video describing his experiences with trying to cleanly laser-mark 3D printed plastics using different methods, and it also happens to be a fantastic tour of all the different laser options available to hobbyists and workshops these days.

Laser marking is a fast and effective way to put things like product names, serial numbers, and other information on plastics. [Stefan] wondered whether laser options would be capable of creating clean and professional marks on 3D-printed items, and approached things with his usual attention to detail.

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2026 Frikkin Lasers Contest: Steampunk, 360 O-Scope Does It With Tubes

June 17, 2026 by Tyler August 10 Comments

Audiophiles all know everything sounds better fed through vacuum tubes, but did you know visualizers look better with them, too? That’s what we’re forced to conclude looking at the Tachyscope Laser, a 360-degree oscilloscope display that is [Daniel Ross]’s entry into the ongoing Frikkin Lasers contest.

The diagram makes it look easier than building it probably was.

The laser is a good old-fashioned helium–neon tube — something we see less and less of in this era of solid state lasers — and the wavelength gives the waveform display a retro charm. The actual display is unique in our experience, with the beam shining up through a hollow shaft to bounce off a galvanometer mirror on a spinning platform. Galvo sweeps the laser across a translucent target, which creates the waveform by persistence of vision as it spins at 100 RPM or so.

Does the fact that the audio signal feeds through a tube amp to drive the single galvanometer actually improve the visuals? Only in the sense that those tubes make the steampunk-style enclosure look really, really cool, as does the exposed laser tube. That all of the steampunk elements obviously have a point to them rather than just being a another “glue some gears on it” project is icing on the laser-flavored cake.

The contest runs until July 23rd, so there’s lots of time to get laserin’ — and remember that there are categories for DIY lasers and anything that isn’t a display, just in case you think this project puts the bar too high for a light show. We’ve actually featured one of [Daniel]’s tachyscope waveform visualizers before, but that one, madly enough, spun an actual CRT.

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Image of an elf projected by the laser scanner

2026 Frikkin Lasers Contest: Glow Engine Is Like An Open Air Slow Scan CRT

June 16, 2026 by Tyler August 10 Comments

Slow-scan CRTs were never exactly common compared to their faster cousins, but given the popularity of Slow Scan TV (SSTV) amongst hams and NASA broadcasts, many of you are probably familiar with them. The slow scan rate of SSTV meant it required much less bandwidth, but in the early days you needed a CRT with a long-persistence phosphor to hold onto the image. [AJRussell]’s Glow Engine works much the same, with one key difference — instead of cathode rays, he’s using a frikkin laser beam.

In this case, the phosphor is Strontium Aluminate, the same stuff that gives most glow-in-the-dark toys and filament its kick. Energized by a 405 nm laser of questionable wattage, the phosphor will glow for several seconds, allowing the creation of an image. So while this is a laser projector, it works more like a CRT than most galvo projectors, which rely on Persistence of Vision to create an image. Here it’s persistence of fluorescence.

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The Frikkin Lasers Contest Starts Now

May 28, 2026 by Elliot Williams 8 Comments

We don’t need to tell you: lasers are awesome. Those tiny red beams aren’t just for frustrating cats, but can do real work, be a source of infinite beauty, or constitute a science project in its own right — and you can win a $150 DigiKey gift certificate simply by writing your project up on Hackaday.io. The contest runs until July 23rd.

Of course, red lasers are only the beginning. If you have enough energy to move electrons into higher orbitals, you can make nearly anything lase. RGB setups can be breathtaking. Powerful IR and UV lasers are real tools. And the DIY side of lasering combines physics and electronics, with a spicy side of danger that needs to be contained.

We love laser builds of all sorts, and we’d like to see yours! Create a new Hackaday.io project that features what you’re working on, and we’ll pick our three favorites for a $150 gift certificate courtesy of this contest’s sponsor, DigiKey.

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A 3D-printed telescope with an infrared laser on the side is pointed out the window of a building at night.

Long-Range Night Vision With An Infrared Laser

May 18, 2026 by Aaron Beckendorf 19 Comments

Most consumer-grade night vision devices are basically a standard camera without the usual filter to block near infrared (NIR) light, which are then paired with a NIR light source that’s not visible to the human eye. Unlike the passive night vision provided by an image intensifier tube, these can’t resolve objects beyond the beam of their illumination source. On the other hand, if, as [Project 326] did, you use an infrared laser to illuminate the scene, you can still get a very long range out of these devices.

[Project 326]’s device consists of a previously-built reflecting telescope focusing a distant scene in to a webcam with the infrared filter removed, with the infrared laser illuminating the scene. Finding a suitable laser took some effort: the first option, a secondhand fiber-coupled industrial laser, was accidentally over-volted and destroyed during testing. The second had a fiber output which proved extremely hard to terminate, and a third laser couldn’t be collimated correctly. The final laser was a Vertical-Cavity Surface-Emitting Laser (VSEL) diode array element driven at about two Watts and collimated by a small lens.

This illumination setup is safe at a long range, but only at a long range. The laser was strong enough to burn cardboard at close range, but out at about 500 meters, the beam had spread until it was less than a hundredth of the standard safety limit. To make sure that nothing else would get in the way of the beam, it was shone down from the top of a tall building. Testing with a power meter also showed that at a long range, the beam was weaker than expected. It turned out that the wavelength used (940 nm) is attenuated by water vapor, to the point that up to 70% of the beam’s strength was lost before reaching the target. Despite this, and despite a rather linear beam profile, a somewhat dark image was still visible at 650 meters.

If you’re looking for a somewhat more versatile long-range night vision device, check out one based on an image intensifier. Another approach is to use a very high-sensitivity camera.

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