Question

Question 24 (1 point) In thin film problems, the condition for bright reflection when 1 wave (only) is phase shifted becomes 2t = mło 2t = (m + 1/2) 20 2t = moln Onone of these 2t = (m + 1/2)lo/n

Answer 1

a B 0 n₂ = Water 1.33 24. considea thin film of of thickness t and refractive index h in air such that no ankh, consider Roy falls falls on interface of the air-thin n=1 interface at the incident angle Oi and ongle of refraction in this film is of t from geomeby D The Optical path difference between the reflected Rays OA and B C is antcost, when a ray goes from rareer to densor medium then the reflected say has the extra bhose difference of a of path difference of /. and There is no phase difference Pn transmitted Rays. so There is additional bath difference() between the reflected says OA and BC. The total fath difference A = 2ntcos On Id for normal incidence 50 ant id for Bright constructive interference A should equal to ml ant & h = mi <=> ant = (m+++ 27 - (m + %)1 where n=0,1,2,3 on 7 2 08 This is the condition for Boight reflection.