Thin film interference explained

Thinfilm interference is a natural phenomenon in which light waves reflected by the upper and lower boundaries of a thin film interfere with one another, either enhancing or reducing the reflected light. How it works in soap bubbles, butterfly wings, and antireflective. This form of interference is commonly called thin film interference and. When the thickness of the film is an odd multiple of one quarterwavelength of the light on it, the reflected waves from both surfaces interfere to cancel. This type of interference is the reason that thin films, such as oil or soap bubbles, form. Explain how the patterns change for each specific example. This form of interference is commonly called thin film interference and provides another line of evidence for the wave behavior of light. An easytounderstand introduction to thinfilm interference and iridescence. Pdf thinfilm thickness profile measurement by three. Constructive and destructive interference of light waves is also the reason why thin films, such as soap bubbles, show colorful patterns. Observable interference effects are not limited to the doubleslit geometry used by thomas young. These streaks of color are the result of the interference of light by the very thin film of oil that is spread over the water surface. Thinfilm interference is also what happens on the surface of a cd or dvd, where the protective lacquer coating acts as the thin film.

Thinfilm interference is a natural phenomenon in which light waves reflected by the upper and. In this video i will show you how to calculate the thickness of the thinfilm of oil. Thinfilm interference why are there colors in soap bubbles. The phenomenon of thinfilm interference results whenever light reflects off two surfaces separated by a distance comparable to its wavelength. Thinfilm interference is the interference of light waves reflecting off the top surface of a film with the waves reflecting from the bottom surface. Thin film interference college physics bc open textbooks. Various possible film configurations and the related equations are explained in more detail in the examples below. One feature of thin film interference and diffraction gratings is that the pattern shifts as you change the angle at which you look or move your head. Thin film interference summary the physics hypertextbook.

The film between the surfaces can be a vacuum, air, or any transparent liquid or solid. Thin film interference occurs when light reflects multiple times off the two sides of a thin transparent material. Find examples of thin film interference and gratings around you. A short quiz on the key concepts in the thin film interference unit. What we have in both cases is light waves interfering in a thin film of soap or oil, so its an example of whats called thinfilm interference. Learn how interference of reflected waves causes oil on water to appear all rainbowy. After watching this video, you will be able to explain how thin film interference works, give examples of. Light striking a thin film is partially reflected ray 1 and partially refracted at the top surface. Answers to all the questions will be presented at the end of the quiz. If the thickness of the film is on the order of the wavelength of light, then colorful patterns can be obtained, as shown in the image on the right. Interference in thin films and derivation of conditions for brightness and darkness in thin films explained by dr.