Interference Flashcards
With a double slit, when the two waves travel the same distance, is the fringe bright or dark?
Bright!
-also normally in the center
In double slit, if the waves travel a different distance, is the fringe always dark?
Nope
When waves travel different distances, when is the fringe bright?
When the difference is distance is by 1 wavelength
When the waves travel different distances, when is the fringe dark?
When the difference is by a wavelength and a half or some form of a half
what is needed for the proper condition for interference?
- monochromatic light (same color, same wavelength)
- mutual coherence(protons don’t spread)
interference obeys the laws of what?
conservation of energy
which type of interference is for bright fringes and what type is for dark?
bright=constructive
dark=destructive
as the slit distance narrows, the angle gets…
bigger!
-angle increases as slit distance narrows
for a fixed wavelength, what happens the the width of the fringes in regards to d (slit distance)
smaller d=slits closer together=wider fringe
larger d=slits farther apart=narrower fringe
for a fixed slit distance (d), what happens to the width of the fringes in regards to wavelength?
larger wavelength=wider fringes=more spread out
smaller wavelength=narrower fringes=less spread out
what color has a wider fringe, blue or red?
red, they are spread out farther because it has a larger wavelength
white light illumination has what kind of fringes?
colored
if the width of the fringes is reduced, is the angle reduced or greater?
reduced!!!!!!!
-reduced wavelength=reduced angle=reduced space between orders=reduced width of fringe
how can a clinician bypass the the optics (cataract) to look at the neural system?
-use two coherent points in a clear part of the pupil and a 100% contrast fringe forms on the retina as an interference pattern
thin film interference is based on what two conditions?
- path difference
- phase change
