Experiment 16: single slit diffraction, Introduction, Procedure – PASCO OS-8500 INTRODUCTORY OPTICS SYSTEM User Manual
Page 43
012-02744K
Introductory Optics System
®
37
EQUIPMENT NEEDED:
-Optical Bench
-Light Source
-Ray Table Base
-Diffraction Scale
-Component Holder
-Diffraction Plate
-Slit Mask
-Color Filters (Red, Green, Blue/Green). Perform in a
well lighted room.
Introduction
If you look closely at a two slit interference pattern, you will notice that the intensity of the fringes varies.
This variation in intensity forms an interference pattern of its own that is independent of the number of
slits or the separation between the slits. In fact, two slits are not required to see this pattern; it can be seen
most clearly when light passes through a single, narrow slit.
In this experiment you will compare the single slit diffraction pattern with the double slit pattern, and
then use the single slit pattern to measure the wavelengths of red, green, and blue light.
Procedure
Setup the equipment as shown in Figure 16.1. Look through each 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.)__________________________________________
_____________________________________________________________________________.
Experiment 16: Single Slit Diffraction
Figure 16.1 Equipment Setup
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DIF
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AC
TIO
N P
LA
TE
A B
C
D
E
DIF
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LAT
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J I H
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Diffraction Scale
Slot
Ray Table
Base
Diffraction
Plate
Window
Slit Mask