PHYS 1C Lecture Notes - Lecture 10: The Joshua Files, Wavefront, Electric Field
Light from the sun is produced by the vibrations of
multitude of atoms located there
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Each atoms produces a wave with its own orientation of
the electric field
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All directions of the electric field vector are equally
possible and are in a plane to the direction of propagation
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This type of wave is known as an unpolarized wave
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Polarization of Light
In order to create sustained interference, you need two
sources with identical wavelengths (monochromatic) that
are coherent.
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Interference
Two narrow slits, S1 and S2, can act as sources of waves.
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The waves emerging from the slit originates from the
same wavefront and therefore are always in phase
(coherence)
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The light from two slits forms a visible pattern on a screen
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The pattern consists of a series of bright and dark parallel
bands called fringes
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The fringe pattern formed by a Young's Double Slit
Experiment would like
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Alternating bright and dark fringes are created
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Constructive interference occurs where a bright fringe
appears
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Destructive interference results in a dark fringe
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In terms fo the distance that the light travels, we see that
for a point above the center spot the distance traveled by
the lower wave, r2, is longer than the upper wave, r1.
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The path length difference, will be:
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Double Slit Experiment
Using trigonometry we find that the path length difference si related to the slit difference, d, and
the angle theta by
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Thus, for constructive interference to occur
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(10) Lecture 27A Interference and Double Slit Experiment
Wednesday, April 25, 2018
1:00 PM
week 4 Page 1
Document Summary
(10) lecture 27a interference and double slit experiment. Light from the sun is produced by the vibrations of multitude of atoms located there. Each atoms produces a wave with its own orientation of the electric field. All directions of the electric field vector are equally possible and are in a plane to the direction of propagation. This type of wave is known as an unpolarized wave. In order to create sustained interference, you need two sources with identical wavelengths (monochromatic) that are coherent. Two narrow slits, s1 and s2, can act as sources of waves. The waves emerging from the slit originates from the same wavefront and therefore are always in phase (coherence) The light from two slits forms a visible pattern on a screen. The pattern consists of a series of bright and dark parallel bands called fringes. The fringe pattern formed by a young"s double slit. Constructive interference occurs where a bright fringe appears.
