Documentation
What Photonica is
Photonica is a laboratory for light. You put a laser, some glass and a screen on a bench, and it works out what the light does — not an animation of what light roughly looks like, but the actual physics, computed for every ray, every wavelength and every surface, thirty times a second.
What it actually computes
Most optics software picks one model and stops there. Photonica carries several at once, because real light does:
- Rays with a wavelength. A white beam is dozens of separate colours travelling together. Each one bends by its own amount in every glass, because the glass's refractive index genuinely depends on wavelength.
- Energy that adds up. At every surface, Fresnel's equations decide how much light reflects and how much passes. Nothing is invented, and nothing disappears.
- Polarisation. Light carries a full polarisation state through polarisers, wave plates and every reflection, so a quarter-wave plate really does turn linear light into circular light.
- Waves. Where geometry stops being enough — slits, pinholes, gratings, the diffraction limit of a lens — Photonica sums Huygens wavelets instead of drawing rays.
- Time. Every path carries an arrival time computed from the group index of whatever it travelled through. You can stop the clock and see where the light has got to.
Three ways in
These docs are written for three different people. Pick the door that fits.
What it is not
Photonica models sequential and non-sequential ray paths, coherent diffraction at apertures, and polarisation. It does not model nonlinear optics, fluorescence, quantum effects, or thermal lensing under load. Lens design here is real but young: it will happily optimise and tolerance a doublet, and it is not a replacement for a full production tolerance stack with vendor-specific manufacturing data.