of the three single slit apertures in the
Diffraction Plate (Patterns A, B, and C). Examine the diffraction
patterns with and without color filters
over the aperture of the Light Source.
➀ How does the spacing between fringes vary with the width of the
slit?______________________
______________________________________________________________________________.
Compare the single slit patterns with the double slit
patterns.
➁ How does a double slit interference pattern differ from a single
slit pattern? (Compare patterns of equal
slit widths, such as A vs D, or B vs
E.)__________________________________________
_____________________________________________________________________________.
The single slit pattern can be explained using Huygen’s theory.
When a plane wave front
strikes the slit, each point on the slit acts as a point source of
light. Figure 16.2 shows a point P,
far from the slit, where the distance AP = BP + λ. Since light
from point A travels one wave-
length farther than light from point B, the light from these two
points is in phase at point P. But
light reaching point P from the points in between A and B will
vary in phase through a full
360°. For any point from which light reaches point P at a
particular phase, there will be a point
from which light arrives in the exact opposite phase. Because of
this, there is complete cancel-
lation at point P, and a minima (dark fringe) will be seen at that
point.
- Setup The Equipment As Shown In Figure 16 1 Look Through Each Of The Three Single Slit Apertures In The Diffraction Pla 1 (51.03 KiB) Viewed 35 times
1st maximum 1st minimum zeroth maximum Diffraction Scale P AB=W Diffraction Grating Figure 16.2 Geometry of Single Slit Diffraction Ө B Retina of your eye .......! 1st maximum 1st minimum Zeroth maximum 1st minimum 1st maximum
Color Red Green Blue n Data W Table 16.1 X L arctan X/L Calculations Wsin (arctan X/L) = n