Filter Angle Shift Calculator

Calculate the wavelength shift of interference filters due to angle of incidence. Supports both collimated beams (fixed AOI) and convergent beams (f-number).

Input
Collimated Beam Shift
Shifted CWL (\u03BB\u03B8)
\u03BB\u03B8 = \u03BB\u2080 \u00D7 \u221A(1 \u2212 sin\u00B2\u03B8 / n_eff\u00B2)
529.65nm
Wavelength shift (\u0394\u03BB)
Negative = blue shift
-2.3488nm
Shift as % of CWL
-0.44150%
Abridged Optics — Filter Angle Shift Calculator v1.0Uses the standard thin-film angle-shift formula \u03BB\u03B8 = \u03BB\u2080\u221A(1 \u2212 sin\u00B2\u03B8/n_eff\u00B2). Valid for moderate angles (0\u201330\u00B0). For convergent beams, the effective CWL shift is approximated as half the collimated shift at the cone half-angle, and bandwidth broadening as the full collimated shift.

All information, equations, and calculations have been compiled and verified to the best of our ability. For mission-critical applications, we recommend independent verification of all values. If you find an error, please let us know.