For Educators · Thin-Film Coating
Thin-Film Coating for a telescope
Built for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs. Simulate a telescope live below — adjust the inputs and watch it respond, right in your browser.
Thin-Film / AR CoatingLive
interference kills reflections
Controls
Presets
Coat glass with a film a quarter-wavelength thick and its two reflections cancel by destructive interference — an anti-reflection coating. It works best at one wavelength (the reflectance dips to near zero there), giving camera lenses and glasses their faint purple sheen. The same physics makes soap bubbles and oil slicks shimmer with color.
Data Inspector
Ideal thickness (550nm)100 nm
Min reflectance1.26%
Film index1.38
Governing equation
Reading this result: At 100 nm the film is almost exactly quarter-wave for 550 nm, so green-light reflection is nearly cancelled — an ideal AR coating.
Runs locally in your browser — free forever. Scale to the cloud when reality gets heavy.
Also for:StudentsResearchersEngineersHobbyists & MakersK-12 StudentsFirst RespondersGeneral version →
More with Thin-Film Coating
Frequently asked questions
- Is this good for educators?
- Yes — this version of "Thin-Film Coating for a telescope" is framed for educators teaching it to a class. Drop a live demo into a lecture or assign it as a shareable link — no lab installs.
- Do I need to install anything?
- No. It runs in any modern browser, free, with no account required.