This is a low cost yet quite functional 3D printed spectrometer with an optical fiber link. The low profile case is completely 3D printed including a connector for an optical fiber cable (Toslink, same as used for audio devices). The fiber is really practical to measure the optical spectrum in the visible range in many situations. The spectrum is picked up by a recycled laptop camera with USB connector soldered to it. And as a diffraction grating the 1000 lines/mm Grating Slide from ebay are used. All the 3D parts are open source (link below).
Inside of the open fiber spectrometer.
Mount the laptop webcam and the diffraction grating on the holders using some double sided tape. Instruction on how to extract laptop cameras and how to solder on a USB connector can be found on internet.
“Diffraction Grating Slide Holographic Linear 1000 lines/mm Lamp Laser Spectrum”
from ebay for about 1$
The 3D printing files for the case can be found on Thingiverse here.