Bryn McKay. Interference occurs when one or more wave are superimposed Diffraction occurs whenever...
-
Upload
vivian-lamb -
Category
Documents
-
view
213 -
download
0
Transcript of Bryn McKay. Interference occurs when one or more wave are superimposed Diffraction occurs whenever...
Diffraction and Interference
Interference occurs when one or more wave are superimposed
Diffraction occurs whenever a wave encounters an object
Parallel light rays diverge and interfere with one another when passing through a aperture
Factors to this diffraction include: The size of the aperture The wavelength of light
Rays traveling at different distances interfere with one another
Sometimes they completely cancel each other
Diffraction is the slight bending of light as it passes around the edge of an object
A larger aperture with a smaller wave length the bending is unnoticeable.
When the two are closer in size the bend is noticeable to the naked eye
Examples
In the atmosphere Light bends around atmospheric particles Diffracted light can produce fringes of
light, dark or colored bands Light waves are similar to the water When sunlight comes in contact with
cloud droplets Light waves are altered and interact with one
another
Simple Hologram
Made by superimposing two waves from the same light source
Two beams The reference beam hits the photographic plate
normally The object beam hits the plate at an angle
The relative phase between the two beams varies across the photographic plate
The two beams interfere with one another to form an interference pattern
The relative phase of object and reference beam is encoded as the maxima and minima of the fringe pattern
The fringe pattern acts as a diffraction grating
It is partly diffracted The object beam has been reconstructed The diffraction grating created by the two
waves interfering has reconstructed the object beam
This is a hologram
Vocab
Diffraction-the bending of waves around obstacles in their path
Aperture- an opening, as a hole, slit, crack, etc. Resolving Power- the ability of an optical
instrument to form separate images of two objects that are close together
Superimposing-to place, or set over, above, or on something else-to put or join as an addition
Fringe Pattern-one of the alternate light and dark bands produced by diffraction or interference
Reconstructed- Recreate or make again