University Physics Volume 3

# Key Terms

### Key Terms

Bragg planes
families of planes within crystals that can give rise to X-ray diffraction
destructive interference for a single slit
occurs when the width of the slit is comparable to the wavelength of light illuminating it
diffraction
bending of a wave around the edges of an opening or an obstacle
diffraction grating
large number of evenly spaced parallel slits
diffraction limit
fundamental limit to resolution due to diffraction
hologram
three-dimensional image recorded on film by lasers; the word hologram means entire picture (from the Greek word holo, as in holistic)
holography
process of producing holograms with the use of lasers
missing order
interference maximum that is not seen because it coincides with a diffraction minimum
Rayleigh criterion
two images are just-resolvable when the center of the diffraction pattern of one is directly over the first minimum of the diffraction pattern of the other
resolution
ability, or limit thereof, to distinguish small details in images
two-slit diffraction pattern
diffraction pattern of two slits of width D that are separated by a distance d is the interference pattern of two point sources separated by d multiplied by the diffraction pattern of a slit of width D
width of the central peak
angle between the minimum for $m=1m=1$ and $m=−1m=−1$
X-ray diffraction
technique that provides the detailed information about crystallographic structure of natural and manufactured materials