CubeRaman 3D-printed – A 3D-printed Raman spectrometer called CubeRaman aims to make molecule identification far more accessible by pairing a cheap 532-nm laser module with a simplified optical path and a housing built from 3D-printed parts.
Light doesn’t always bounce back the same way. When it hits a surface. some photons give up energy to the vibrational motion of molecules and scatter away with a lower energy—and a longer wavelength. That shift is Raman scattering, and its exact wavelength pattern acts like a fingerprint for the molecules being illuminated.
In Raman spectroscopy, measuring those shifts usually means expensive, elaborate instruments. But [Allegedly Science] built a simpler system with what it calls surprising sensitivity—one that packages the core optical path inside a cube.
The instrument is named the CubeRaman, after the cube-shaped body that holds the optics. It starts with a cheap 532-nm laser module as a monochromatic light source. then uses a bandpass filter to eliminate stray infrared light. From there, the beam reflects off a 45-degree dichroic mirror and heads through a microscope objective onto the sample.
Raman-shifted light scatters back through the same objective, passes through the dichroic mirror again, then is sent through a long-pass optical filter. Finally, an achromatic lens focuses that returning light onto the slit of a spectrometer.
The housing isn’t just compact—it’s manufactured in a way that’s meant to be repeatable. The entire body is 3D-printed, along with most of the kinematic mounts. Those mounts use adjustment screws that run through inserts, with the tips of the screws held in place by magnets. The result is an instrument that can be tuned without the heavy machining usually associated with precision optics.
[Allegedly Science] tested the system first with a raw diamond, and it showed the expected Raman shift. When the experiment moved to chemistry inside a glass bottle, the results shifted—mainly returning the signature of silica. The work makes it clear why: thin-walled cuvettes became essential for seeing beyond the container’s own materials.
Even the choice of bottle mattered. Ethanol inside a plastic bottle produced results that changed with the focal distance. Depending on where the setup was focused, the system could detect the characteristic shift of ethanol or instead pick up polypropylene.
The project doesn’t claim it’s a finished product. [Allegedly Science] says there’s still room for improvement. especially by eliminating stray light and using a narrower slit in the spectrometer. The need for that separate spectrometer is a key tradeoff: the CubeRaman design simplifies the optical side. but it doesn’t remove the requirement to pair it with spectrometer hardware.
For anyone who wants to try Raman spectroscopy without building an entire lab-grade instrument from scratch, that’s the point of the CubeRaman. It’s an attempt to turn a traditionally costly technique into something far more approachable—one 3D-printed cube at a time.
A video of the setup is available at https://www.youtube.com/watch?v=bUxc6mWsTgc.
Raman spectroscopy CubeRaman 3D-printed spectrometer 532-nm laser Raman scattering optical filters dichroic mirror spectrometer slit open source science