An open-source fiber spectrograph designed by evolutionary algorithm. Printable housing, off-the-shelf optics, USB spectral data output.
A fixed-grating Czerny-Turner fiber spectrograph that takes light in via SMA-905 fiber and outputs spectral data over USB. Cylindrical mirrors for astigmatism correction, the same class of instrument as Ocean Optics USB4000 and Flame.
The geometry generator is authoritative: the same code path the fitness function traces is what gets exported as printable STEP files.
Optical train (v0 — Thorlabs COTS):
25 µm fiber (NA 0.12) → HASMA → F1 (cyl. fold) → M1 (cyl. collimator) → Grating (600 g/mm) → M2 (spherical camera) → TCD1304 CCD → USB
Key specs: ~15 nm/mm dispersion, 400-700 nm band, <1 nm resolution (0.50 nm FWHM measured at 404.7 nm Hg line).
# Clone the sibling solver repo
git clone https://github.com/dookaloosy/evolutionary-solver.git ../evolutionary-solver
# Bootstrap (creates .venv, installs everything)
./bootstrap.sh
source .venv/bin/activate
# Fetch third-party STEP files (detector board, not redistributable)
./fetch_vendor_steps.sh# Run tests
python -m pytest tests/
# Run the optimizer
python run_optimizer.py czerny --n_workers 12
# Export from baseline (layout diagram + CAD + STEP files + BOM CSV)
python export.py --baseline data/czerny_baseline_v0_design.toml --layout --cad --step
# Spot diagrams
python scripts/spot_panel.py --baseline data/czerny_baseline_v0_design.toml
# Build the paper (requires LaTeX)
./build_paper.shcontroller (installed by the bootstrap) is the desktop application
and CLI for the TCD1304 detector: live spectrum, capture with
provenance headers, and live wavelength calibration against a CFL
lamp.
controller # desktop app (the primary tool)
controller capture -e 25ms -n 4 # scripted capture -> output/
controller calibrate output/capture.<stamp>.tcd1304 # offline recalibration
The detector electronics and firmware are
drmcnelson's open-source projects;
the instrument requires his firmware on the Teensy controller board.
controller is an independent, MIT-licensed client written against
the firmware's documented serial interface — no upstream host
software is needed.
The full design narrative is in the paper (open-spectrograph.tex).
Pre-built PDFs are available on the Releases page.
Section sources in docs/:
Software (source code, scripts, simulation): MIT Hardware (STEP files, BOM, mechanical designs): CERN-OHL-P v2
Third-party vendor STEP files are not included due to redistribution
restrictions. Optic solids are generated procedurally from BOM parameters.
Run ./fetch_vendor_steps.sh for the detector and controller board STEPs
(CC BY-NC-SA 4.0 by Dr. Mitch Nelson).