The interference between two independent beams of light, often called optical heterodyne detection, is of considerable theoretical and practical importance. This note concentrates on considerations of instrumentation and technique that arise in demonstrating optical heterodyning, and describes three experimental demonstrations of the phenomenon.

1.
P. A. M. Dirac, The Principles of Quantum Mechanics (Oxford U.P., Oxford, 1930), p. 15.
2.
Roy J.
Glauber
, “
Dirac’s Famous Dictum on Interference: One Photon or Two?
Am. J. Phys.
63
,
12
(
1995
);
H.
Paul
, “
Interference between independent photons
,”
Rev. Mod. Phys.
58
,
209
231
(
1986
).
3.
Electro-Optics Technology, Inc. (Traverse City, MI), Model ET-2010 photodetector.
4.
Melles-Griot, Inc., “Introduction to Helium-Neon Lasers,” http://www.mellesgriot.com/pdf/0044.2-44.3.pdf.
5.
Anritsu America, Inc. (Rochelle Park, NJ), MS 610B rf spectrum analyzer.
6.
Hewlett-Packard (Agilent, Colorado Springs, CO), Model 54820A Infinium 0.5 GHz, 2 GSamples/s oscilloscope.
7.
Åsa
Lindberg
, “
Mode frequency pulling in He-Ne lasers
,”
Am. J. Phys.
67
,
350
353
(
1999
), and references therein.
8.
Chandrasekhar
Roychoudhuri
and
Robert H.
Noble
, “
Demonstrations using a Fabry-Perot. II. Laser modes display
,”
Am. J. Phys.
43
,
1057
1059
(
1975
).
9.
Amnon Yariv, Optical Electronics (Holt, Rinehart, and Winston, New York, 1985), Chap. 12;
D. T.
Pierce
and
R. L.
Byer
, “
Experiments on the Interaction of Light and Sound for the Advanced Laboratory
,”
Am. J. Phys.
41
,
314
325
(
1973
).
10.
NEC USA, Inc. (Rochelle Park, NJ), Model OD-8813A acousto-optic modulator, as described in
J. A.
Deblaquiere
,
K. C.
Harvey
, and
A. K.
Hemann
, “
Time-of-flight measurement of the speed of light using an acousto-optic modulator
,”
Am. J. Phys.
59
,
443
447
(
1991
).
11.
New Focus, Inc. (Santa Clara, CA), Model 6013 Vortex laser systems.
12.
Melles-Griot, Inc. (Irvine, CA), Model 03 PBS 065 beamsplitter cube.
13.
S. F.
Jacobs
, “
Optical heterodyne (coherent) detection
,”
Am. J. Phys.
56
,
235
245
(
1988
).
14.
New Focus, Inc., “Generating Microwaves with Diode Lasers,” http://www.newfocus.com/Online_Catalog/Literature/gener.pdf.
15.
See, for example,
G. P.
Barwood
,
P.
Gill
, and
W. R. C.
Rowley
, “
Frequency measurements on optically narrowed Rb-stabilized laser diodes at 780 nm and 795 nm
,”
Appl. Phys. B: Photophys. Laser Chem.
53
,
142
147
(
1991
).
16.
David J.
Jones
,
Scott A.
Diddams
,
Jinendra K.
Ranka
,
Andrew
Stentz
,
Robert S.
Windeler
,
John L.
Hall
, and
Steven T.
Cundiff
, “
Carrier-envelope phase control of femtosecond mode-locked lasers and direct optical frequency synthesis
,”
Science
288
,
635
639
(
2000
).
This content is only available via PDF.
AAPT members receive access to the American Journal of Physics and The Physics Teacher as a member benefit. To learn more about this member benefit and becoming an AAPT member, visit the Joining AAPT page.