This is a tool used to design sinusoidal frequency modulation (SFM) interferometer layouts.
Check it out → https://blueskyspectroscopy.github.io/sfm-designer
SFM interferometry was the topic of my PhD thesis, which can be found at A cryogenic multiaxis range-resolved laser interferometer.
A. Christiansen. "A cryogenic multiaxis range-resolved laser interferometer". Doctoral thesis, University of Lethbridge, 2024. Handle: 10133/6671.