This preview shows page 1. Sign up to view the full content.
Unformatted text preview: 12. Consider Huygens’ explanation of diﬀraction phenomena. When A is in place only the Huygens’ wavelets
that pass through the hole get to point P . Suppose they produce a resultant electric ﬁeld EA . When B
is in place, the light that was blocked by A gets to P and the light that passed through the hole in A
is blocked. Suppose the electric ﬁeld at P is now EB . The sum EA + EB is the resultant of all waves
that get to P when neither A nor B are present. Since P is in the geometric shadow, this is zero. Thus
EA = −EB , and since the intensity is proportional to the square of the electric ﬁeld, the intensity at P
is the same when A is present as when B is present. ...
View Full Document