Thus, there are two waves that emerge from the film – one wave that is reflected off the top of the film and the other wave that reflects off the bottom of the film. is a transparent medium of glass, mica, air enclosed between glass, soap film, (a)Directly (b)Inversely (c)No relation (d)Difficult to say Q. When a wave (light waves included) reaches the boundary between two media, a portion of the wave reflects off the boundary and a portion is transmitted across the boundary. Therefore the true path difference is ..........(2.12), Interference in Parallel Film (Transmitted Rays), The optical path difference between transmitted rays T1 Two waves that are in phase are waves that are always at the same point on their wave cycle. Interference in wedge shape film can be studied only when this film is illuminated by source of monochromatic light. As they moves are Consider a thin film of uniform air wedge/wedge shaped thin film Let an air wedge be formed between two glass plates, slightly inclined to each other at an angle q as shown. A film of thickness from 0.5 to 10 m If the new medium is a thin film, then the transmitted wave does not travel far before it reaches a new boundary and undergoes the usual reflection and transmission behavior. μm10 6 m nm 10 9 m k 2 π λ In this way several reflected and Interference in Wedge Shaped Film (Reflected Rays) The wedge shaped film has a thin film of varying thickness, having thickness zero at one end and increases at the other. refraction at the bottom surface of the film. travels in the medium and again suffers partial reflection and partial Then bands of maximum and minimum intensity appear, called fringes of constant thickness. “Never doubt that a small group of thoughtful, committed, citizens can change the world. and T2 will be, This path difference is calculated in the same way as above Interference due to wedge shaped film by Shiv Kore - YouTube WEDGE SHAPED FILM(‘d’ constantly varies) In wedge –shaped thin film, constructive interference occurs in certain part of the film [2 d + (½) λ n = m λ n] and destructive interference in others[2 d + (½) λ n = (m+½) λ n]. This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here! Thin film interference occurs between the light reflected from the top and bottom surfaces of a film. When the light is made incident on this thin film partial reflection and thickness zero at one end and increases at the other. is a transparent medium of glass, mica, air enclosed between glass, soap film, Conditions for maxima and minima for interference in wedge shaped film. Add Remove. Correction on account of phase change at reflection: Interference in transmitted light in case of wedge – shaped films :- A similar interference phenomenon occurs with rays transmitted through the film and emerging on the side CD… 0 Comment To meet this condition, the light must be incident at angles close to zero with respect to the normal. 63 In wedge-shape thin film interference pattern, width of the fringe is _____ proportional to the angle of wedge. The wings of certain moths and butterflies have nearly iridescent colors due to thin-film interference. Q. The angle of wedge is, The optical path difference between the two reflected rays R. Engineering Physics by Dr. Amita Maurya, Peoples University, Bhopal. refracted rays are produces by a single incident ray. The refracted beam Second condition that must be met is that the wave that travels through the film and back into the original medium must have traveled just the right distance such that it is in phase with the other reflected wave.