Fringe Analysis Calculator
Multi-mode interferometric calculator — fringe spacing, OPD & phase, Fabry–Pérot parameters, and coherence requirements.
Interferometric measurements appear throughout precision optics in four analytically distinct contexts, each addressed by one mode of this tool. Fringe Spacing & Tilt converts a fringe count across an aperture into fringe period, tilt angle, and total surface height deviation — the core reduction step for test-plate or shear interferograms. OPD & Phase converts a physical path-length difference (µm) into optical path difference (nm), phase (radians and degrees), and fringe order for both single-pass (Mach–Zehnder) and double-pass (Michelson) configurations. Fabry–Pérot computes reflective finesse, free spectral range (Hz and nm), and minimum resolvable linewidth from mirror reflectance, cavity length, and refractive index. Coherence & Source converts source linewidth or spectral bandwidth into coherence length and coherence time, with presets from white light to narrow-linewidth fiber lasers.