Class 12 Physics simulations · Wave Optics

Thin-film interference

Reflect light from the two faces of a thin film and tune its thickness through bright and dark conditions.

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What to notice

Reflection at the first air-to-film surface adds a phase reversal. Some thicknesses cancel reflected light.

Key relation

Optical path difference = 2nt

Try this

Change film thickness and watch the reflected intensity repeat.

What you can change

• Film thickness: 0 to 800 nm
• Film refractive index: 1.2 to 1.8
• Light wavelength: 400 to 700 nm

More in Wave Optics

• Brewster’s angle
• Single slit diffraction
• Diffraction grating orders
• Double slit interference
• Fringe width in Young’s experiment
• Polarisation and Malus’s law
• Resolving two stars (Rayleigh criterion)

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