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YOU CAN BUILD A LASER YOU TUNE TO ANY COLOUR WITH HIGHLIGHTER DYES AND A TURN OF A SCREW

A laser that changes colour when you turn a screw, pumped by 40,000 volts and household dyes.

by The Thought Emporium

FULL CAD BOM FIRMWARE DOCS

WorkshopScience

Built with3D printing

difficulty
●●●●●
time
a weekend-plus
license
GPL-3.0
repo
repo ACTIVE16 stars

WHAT YOU’LL NEED

Videos
1
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COMPAREE VERDICT

This is a tunable dye laser on a workbench, and it is exactly as hard as that sounds. The output is real — rhodamine 6G, fluorescein from highlighters, rhodamine B and coumarin all lase, and turning a screw on the diffraction-grating mirror mount walks you across each dye's colour range. The video also shows a homemade TEA nitrogen laser built from an aluminium plate and foil capacitors, a doorknob-style capacitor, a spark gap and a ZVS-driven flyback at about 40,000 volts. But be clear about what you are seeing: after weeks of failures, the team bought a commercial nitrogen laser to pump the dye cell in a safe enclosure, and the clean colour results come from that setup. The published files are eight STL parts for the optics and the cuvette holder; part dimensions and the working dye concentrations (in 99% ethanol) are shown in the roughly 17-minute video. There is no bill of materials. The maker is explicit that he does not recommend building the TEA laser: the voltages are lethal, it is extremely loud and the light pulses are intense. If you already work with pulsed lasers or high voltage, the files save you a CAD afternoon. If you are coming in cold because the video looked cool, this is not the project.

GOOD TO KNOW

  • —Eight STL designs for the optics mounts and dye cell are on GitHub under GPL-3.0. Commercial use is allowed, but modified versions must stay open under the same licence.
  • —There is no bill of materials. The nitrogen laser pump, high voltage supply, spark gap, capacitors and ZVS driver are described in the video only.
  • —No dimensional drawings or circuit schematics are in the repository; the part dimensions and the circuit diagram are shown on screen in the video.
  • —The dyes are named (rhodamine 6G, fluorescein, rhodamine B, a coumarin), and the working concentrations in 99% ethanol are shown in the video; no vendor links are given.
  • —The maker states repeatedly: the voltages involved are lethal. This is not a weekend electronics project with a safety footnote; it is a high voltage build where one mistake kills you.
  • —This is a demonstration build, not a kit. You are expected to know what a TEA nitrogen laser is and how a diffraction grating selects wavelength before you start.

Parts to buy

9 items

From our check of the build. Exact quantities and part numbers are in the creator’s BOM.

  • Diffraction gratingFind
  • Laser mirrorsFind
  • Cuvettes (or microscope slides for DIY cuvettes)Find
  • 99% ethanolFind
  • Dyes (rhodamine 6G, fluorescein, rhodamine B, a coumarin)Find
  • Acetate sheetsFind
  • Hex barFind
  • ZVS-driven flybackFind
  • Doorknob-style capacitor and spark-gap hardwareFind

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Can I build this?

PrintEight parts: cuvette holder, cuvette insert, microscope slide jig, two mirror mounts, mirror slider, two swing mounts for the lens.
BuyDiffraction grating, laser mirrors, cuvettes (or microscope slides for DIY cuvettes), 99% ethanol, dyes (rhodamine 6G, fluorescein, rhodamine B, a coumarin), and a UV pump: either a commercial nitrogen laser (what the team used for the working results) or the parts for a homemade TEA laser — aluminium plate and foil, acetate sheets, hex bar, a ZVS-driven flyback, a doorknob-style capacitor and spark-gap hardware. No vendor links or part numbers are provided.
Tools3D printer, drill press or mill for the aluminium base plate, high voltage test equipment, laser safety goggles rated for the dye wavelengths, fume extraction, and the confidence to work around voltages that will stop your heart.
SkillsExpert. You need to understand pulsed nitrogen lasers, high voltage safety, optical cavity alignment, and diffraction grating tuning. If you have never built a TEA laser or worked with 40kV circuits, this is not your entry point.
TimeA weekend if you have built nitrogen lasers before and are ordering known parts. A month if you are learning as you go and reverse-engineering dimensions from the video.
Cost$$$. The diffraction grating, laser mirrors, and high voltage components will run you several hundred dollars. Dyes are cheap if you buy small quantities, but the supporting equipment is not. No hard currency figure is given because it depends entirely on what you already own.
SafetyLethal mains voltage and 40,000-volt capacitors. One mistake kills you. Pressurised spark gaps can explode if mishandled. Dye solvents are flammable. You need laser safety goggles rated for every wavelength the dyes emit, and you need to treat this as a high voltage lab build, not a weekend hobby.

Build at your own risk. Projects involve tools, electronics and sometimes mains voltage — follow the creator’s safety notes.

Videos

The nitrogen laser dimensions, high voltage supply, spark gap setup and dye concentrations are explained here. You will need to pause repeatedly and take notes.

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Gallery

Start here

Navigation into the creator’s own docs — we don’t rewrite the guide, we route you to the source.

  1. 1.Watch the full YouTube video and take notes on the nitrogen laser dimensions, high voltage supply, and spark gap setup. The repository has no written documentation. (This is not optional. The video is the manual.)
  2. 2.Print the eight STL files from the repository: cuvette holder, insert, jig, two mirror mounts, slider, two swing mounts. (These are the only published mechanical files. Everything else you reverse-engineer.)
  3. 3.Source the diffraction grating, laser mirrors, and high voltage components. No part numbers or vendors are given. You are expected to know what to buy.(If you do not know what a TEA laser requires, stop here.)
  4. 4.Decide on the pump first: a commercial nitrogen laser (what the team used for the working results) is far safer than the homemade TEA laser. If you build the TEA laser anyway, test it in isolation and never touch it while charged.(High voltage test equipment is not optional. One mistake is fatal.)

Resources

Documentation, files and community threads for this build — we link straight to the original sources and never rehost the creator’s files.

KNOWN ISSUES

  • The repository has no bill of materials, no circuit schematics, and no written build guide. If you were expecting a parts list and assembly instructions, they do not exist.
  • The voltages involved are lethal. The maker states this repeatedly. If you have never worked with high voltage before, this is not the project to learn on.
  • The nitrogen laser dimensions are in the video only, and you will be pausing and measuring from footage. If you need a dimensional drawing, you will be making it yourself.
  • The working dye concentrations are shown on screen in the video, and all must be dissolved in 99% ethanol; note them down, because they are not in the repository.
  • The diffraction grating alignment is finicky. If you have never tuned a dye laser before, expect to spend an afternoon on it even after the optics are aligned.
  • The spark gap sets the firing rate: a simple gap works, and pressurising it lets you control the firing rate and the energy of each pulse.

Can I buy a nitrogen laser instead of building one?

Yes — that is what the team ended up doing. After weeks of trouble with the homemade TEA laser, they bought a commercial nitrogen laser, which is computer-controlled and enclosed, and it is far safer. The published files are for the dye cell and optics only.

How much does it cost to build?

No verified total is available. The diffraction grating, mirrors and high voltage components will run several hundred dollars. Dyes are cheap, but the supporting equipment is not.

Is there a step-by-step build guide?

No. The video explains the theory and shows the build, but you are expected to reverse-engineer dimensions and part selections yourself.

What safety equipment do I actually need?

Laser safety goggles rated for the dye wavelengths, high voltage test equipment, fume extraction for the solvents, and a workspace where a mistake will not kill someone else. This is not a kitchen-table build.

Community builds

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Discussion1

FROM THE COMPAREE TEAM

Forty thousand volts, homemade capacitors, and a screw that sweeps the colour range — and the maker says plainly: one mistake is lethal. If you have built TEA lasers before, what was the hardest part to get right?

CompareeTEAM1mo agoedited

Verification notes: the repository holds the 3D-printable parts as STL files — cuvette holders, a microscope-slide cuvette jig, mirror and lens mounts and a mirror slider — and a short README pointing to the video; the design takes either DIY cuvettes made from microscope slides or commercial quartz cuvettes. There is no bill of materials, no circuit diagram and no written build guide, and the README says the files are as-is and some should probably be tweaked. The video runs about 17 minutes and covers the TEA laser that pumps the dye (two metal rails, homemade foil capacitors, a flyback transformer around 40,000 volts), the dye laser itself, and changing colours, and it shows the part dimensions on screen. The maker is explicit that he does not recommend building one: the voltages are lethal, it is extremely loud, and the light pulses are intense. If you have never worked with high voltage, this is not the weekend project it looks like; if you have, the STLs save you a CAD session. Correction (4 October 2026): we re-checked this page line by line against the project's own repository, documentation and videos, and fixed errors in earlier versions.

The Thought Emporium

A YouTube channel known for ambitious DIY science builds, including gene editing, cell culture, and optics projects. The dye laser video is part of a series on homemade lasers.

GitHub

Star the project on GitHub

DISCLAIMER

  • Comparee is not the author of the projects featured here. All rights to each project belong to its creator — every page links to the original source, and we never host creators’ files.
  • Information is provided without warranty and may become outdated as projects evolve. Prices are indicative bands only — always check the creator’s parts list for current costs.
  • Building and operating any project is at your own responsibility. Protective equipment, safe workshop practice and compliance with local regulations are the builder’s responsibility.
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