26 Interference & Diffraction -- Physical/Wave Optics Thin film interference.
Interference
-
Upload
chris-staines -
Category
Education
-
view
656 -
download
7
Transcript of Interference
interference
Conditions for interference Sound waves Light waves Young’s double slit experiment
Conditions for interference
All waves exhibit interference Constrictive Destructive For Interference:
The sources must be coherent. The sources should be monochromatic
Sound waves
Sound waves leave speakers in phase Relative phase along XY depends on
distance travelled Maximum if path difference = n Minimum if path difference = (n + ½)
Light waves
V. rare to observe light interfering to produce dark region
Usually random polarisation and phase Hence no steady interference pattern 1801: Young produced double slit
experiment
Light bands = maxima – due to constrictive interference
i.e. path difference = n Distance between maxima, w depends on:
1. Slit separation, s
2. Wavelength of light, 3. Distance, D between slits and screen
= ws
D