- This thin film simulator from Tom Walsh at oPhysics shows the transmitted and reflected waves from a thin film. You can independently vary the wavelength, thickness, and indices of refraction with sliders or by entering numbers, as desired.
https://www.ophysics.com/l6.html
- This thin film simulator by Logan Scheiner and Andrew Duffy functions similarly, but with predefined, selectable light frequencies (red, green, and blue). This simulator loads more quickly on many systems than the oPhysics version, which may be useful in lectures, while the greater precision of the other may be more valuable for student activities out of class.