We demonstrate how to construct and operate a simple and affordable apparatus for producing coherent effects in atomic vapor and for investigating their applications in time-keeping and magnetometry. The apparatus consists of a vertical cavity surface emitting diode laser directly current-modulated using a tunable microwave oscillator to produce multiple optical fields needed for the observation of coherent population trapping. This effect allows very accurate measurement of the transition frequency between two ground state hyperfine sublevels, which can be used to construct a coherent population trapping-based atomic clock.
REFERENCES
1.
M. D.
Lukin
, “Colloquium: Trapping and manipulating photon states in atomic ensembles
,” Rev. Mod. Phys.
75
, 457
–472
(2003
).2.
E.
Arimondo
, “Coherent population trapping in laser spectroscopy
,” Prog. Opt.
35
, 257
–354
(1996
).3.
M.
Fleischhauer
, A.
Imamoglu
, and J. P.
Marangos
, “Electromagnetically induced transparency: Optics in coherent media
,” Rev. Mod. Phys.
77
, 633
–673
(2005
).4.
J.
Vanier
, “Atomic clocks based on coherent population trapping: A review
,” Appl. Phys. B
81
, 421
–442
(2005
).5.
J.
Comparo
, “The rubidium atomic clock and basic research
,” Phys. Today
60
(11
), 33
–39
(2007
).6.
R.
Wynands
, “The atomic wrist-watch
,” Nature (London)
429
, 509
–510
(2004
).7.
M.
Fleischhauer
and M. O.
Scully
, “Quantum sensitivity limits of an optical magnetometer based on atomic phase coherence
,” Phys. Rev. A
49
, 1973
–1986
(1994
).8.
P. D. D.
Schwindt
, S.
Knappe
, V.
Shah
, L.
Hollberg
, J.
Kitching
, L.-A.
Liew
, and J.
Moreland
, “Chip-scale atomic magnetometer
,” Appl. Phys. Lett.
85
, 6409
–6411
(2004
).9.
R. W.
Boyd
and D. J.
Gauthier
, “Slow and Fast Light
,” in Progress in Optics
, edited by E.
Wolf
(Elsevier
, Amsterdam
, 2002
), Vol. 43
Chap. 6, pp. 497
–530
.10.
M. D.
Eisaman
, M.
Fleischhauer
, M. D.
Lukin
, and A. S.
Zibrov
, “Toward quantum control of single photons
,” Opt. Photonics News
17
, 22
–27
(2006
).11.
M. D.
Lukin
and A.
Imamoglu
, “Nonlinear optics and quantum entanglement of ultraslow single photons
,” Phys. Rev. Lett.
84
, 1419
–1422
(2000
).12.
D.
Budker
, D. J.
Orlando
, and V. V.
Yashchuk
, “Nonlinear laser spectroscopy and magneto-optics
,” Am. J. Phys.
67
, 584
–592
(1999
).13.
D. J.
Griffiths
, Introduction to Quantum Mechanics
, 2nd ed. (Pearson Prentice Hall
, Upper Saddle River, NJ
, 2005
).14.
15.
C.
Affolderbach
, A.
Nagel
, S.
Knappe
, C.
Jung
, D.
Wiedenmann
, and R.
Wynands
, “Nonlinear spectroscopy using a vertical-cavity surface-emitting laser (VCSEL)
,” Appl. Phys. B
70
, 407
–413
(2000
).16.
G. B.
Arfken
and H. J.
Weber
, Mathematical Methods for Physicists
, 6th ed. (Harcourt
, San Diego
, 2005
).17.
M.
Stähler
, R.
Wynands
, S.
Knappe
, J.
Kitching
, L.
Hollberg
, A.
Taichenachev
, and V.
Yudin
, “Coherent population trapping resonances in thermal vapor: versus line excitation
,” Opt. Lett.
27
, 1472
–1474
(2002
).18.
M.
Merimaa
, T.
Lindvall
, I.
Tittonen
, and E.
Ikonen
, “All-optical atomic clock based on coherent population trapping in
,” J. Opt. Soc. Am. B
20
, 273
–279
(2003
).19.
N.
Belcher
, “Development of a prototype atomic clock based on coherent population trapping
,” BS Thesis, Department of Physics, The College of William & Mary (May, 2008
);available at ⟨ixnovi.people.wm.edu/publications/ClockDocs.html⟩.
20.
K. L.
Corwin
, Z.-T.
Lu
, C. F.
Hand
, R. J.
Epstain
, and C. E.
Wieman
, “Frequency-stabilized diode laser with the Zeeman shift in an atomic vapor
,” Appl. Opt.
37
, 3295
–3298
(1998
).21.
V. V.
Yashchuk
, D.
Budker
, and J.
Davis
, “Laser frequency stabilization using linear magneto-optics
,” Rev. Sci. Instrum.
71
, 341
–346
(2000
).22.
Although such a calculation gives a good order of magnitude estimate of the coherence lifetime, some atoms moving along the laser beam interact with light much longer, giving rise to additional narrow resonances. See, for example,
S.
Briaudeau
, D.
Bloch
, and M.
Ducloy
, “Sub-Doppler spectroscopy in a thin film of resonant vapor
,” Phys. Rev. A
59
, 3723
–3735
(1999
);A.
Sargsyan
, D.
Sarkisyan
, and A.
Papoyan
, “Dark-line atomic resonances in a submicron-thin Rb vapor layer
,” Phys. Rev. A
73
, 033803
(2006
).23.
E.
Arimondo
, “Relaxation processes in coherent-population trapping
,” Phys. Rev. Lett.
54
, 2216
–2223
(1996
).24.
Y.
Xiao
, I.
Novikova
, D. F.
Phillips
, and R. L.
Walsworth
, “Diffusion-induced Ramsey narrowing
,” Phys. Rev. Lett.
96
, 043601
(2006
).25.
E. E.
Mikhailov
, I.
Novikova
, Y. V.
Rostovtsev
, and G. R.
Welch
, “Buffer-gas induced absorption resonances in Rb vapor
,” Phys. Rev. A
70
, 033806
(2004
).26.
The official site of Bureau International des Poids et Mesures is ⟨www.bipm.org/en/si/base-units/⟩.
27.
An overview of Allan variance is given by
David W.
Allan
at ⟨www.allanstime.com/AllanVariance/⟩.© 2009 American Association of Physics Teachers.
2009
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