We show that diffraction patterns can be directly simulated by a computer program implementing a lock-in algorithm. The two distinct physical topics, namely, single-slit diffraction and lock-in detection, are juxtaposed to highlight the common underlying physical principle in the context of the power spectrum of source signals arising from Fourier analysis.
REFERENCES
1.
D. C.
Giancoli
, Physics for Scientists and Engineers with Modern Physics
, 4th ed. (
Pearson Prentice Hall
,
Upper Saddle River, NJ
, 2008
), Chap. 35, pp. 903
–909
.2.
D. T.
Chuss
, “
A software-based lock-in measurement for student laboratories
,” Am. J. Phys.
86
(2
), 154
–158
(2018
).3.
K. G.
Libbrecht
,
E. D.
Black
, and
C. M.
Hirata
, “
A basic lock-in amplifier experiment for the undergraduate laboratory
,” Am. J. Phys.
71
(11
), 1208
–1213
(2003
).4.
Note that physical employment of a data acquisition card is not necessary in the present study; the sampling time (or sampling frequency) is directly related to the number of data points.
5.
W. H.
Press
,
S. A.
Teukolsky
,
W. T.
Vetterling
, and
B. P.
Flannery
, Numerical Recipes: The Art of Scientific Computing
, 3rd ed. (
Cambridge U. P
.,
New York, NY
, 2007
), Chap. 12.6.
G.
Heinzel
,
A.
Rüdiger
, and
R.
Schilling
, Spectrum and Spectral Density Estimation by the Discreet Fourier Transform (DFT) Including a Comprehensive List of Window Functions and Some New Flat-Top Windows
(
Max-Planck Institut für Gravitationphysik
,
Hannover
, 2002
).7.
E.
Hecht
, Optics
, 4th ed. (
Pearson Addison Wesley
,
San Francisco, CA
, 2001
), Chap. 11.© 2024 Author(s). Published under an exclusive license by American Association of Physics Teachers.
2024
Author(s)
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