nonlinear magneto-optical resonances for systems with j~100 observed in k 2 molecules m. auzinsh, r....
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Nonlinear magneto-optical resonances for systems with
J~100 observed in K2 molecules
M. Auzinsh, R. Ferber, I. Fescenko, L. Kalvans, M. TamanisLaser Centre, The University of Latvia
Iļja Feščenko Rīga, 05.10.2011
Creation and destruction of atomic coherence
Introduction Experiment Theory Results Discussions Conclusion
z
x
y
Jg =1
Je =1
B
Hanle effect and configuration
Introduction Experiment Theory Results Discussions Conclusion
Jg =1
Je =1
M=-1 M=0 M=+1
Magneto-optical effects
Manifestations:•dark and bright resonances,•coherent population trapping,•electromagnetically induced transparency,•electromagnetically induced absorption,•slow light etc.
Introduction Experiment Theory Results Discussions Conclusion
Applications:•opto-electronics,•medicine,•precise measurement techniques,•magnetometry...
Diatomic molecules
Introduction Experiment Theory Results Discussions Conclusion
History:•First report in 1972 for the I2 molecule,
•analysis using the classical treatment in terms of the balance equations for the classical probability density, in 1976. •First direct experimental studies in 1979 for the potassium and sodium,•A model was developed in 1988, applied an expansion of the density matrix via polarization (multipole) moments
Motivation:•to revisit the nonlinear ground state Hanle effect of a diatomic molecule with J~100,•to apply the detailed theoretical treatment,•to study in detail the peculiarities observed in earlier works.
Cell
Introduction Experiment Theory Results Discussions Conclusion
to vacuum system
K2 molecules
Introduction Experiment Theory Results Discussions Conclusion
a) X1g+(2,99)→ B1u(0,99)
b) X1g+(2,105)→ B1u(0,106) 15400 15300 15200 15100 15000 14900 14800 14700 14600
0
10
20
30
40
50
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90
100Spectrum fragment at the LIF Q-progression in 39K
2
inte
nsity
, rel
frequency, cm-1
Registration
Excitation
Set-up
Introduction Experiment Theory Results Discussions Conclusion
Polarizer
λ/2
Diode Laser
Power supplyMonochromator
Polarizer
PMT
LensMagnet Coils
Theoretical model
Introduction Experiment Theory Results Discussions Conclusion
Calculations
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Dependence on atomic density
Introduction Experiment Theory Results Discussions Conclusion
Dependence on laser power density
Introduction Experiment Theory Results Discussions Conclusion
Q and R excitation
Introduction Experiment Theory Results Discussions Conclusion
Dependence on laser power density
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R =27 R =10
Rabi frequency
Introduction Experiment Theory Results Discussions Conclusion
Multipole moments
Introduction Experiment Theory Results Discussions Conclusion
J
J
=L
=L
Summary
Introduction Experiment Theory Results Discussions Conclusion
• Nonlinear magneto-optical resonances have been studied for systems with large angular momentum (J~100) in K2 molecules.
• Dark resonances have been theoretically predicted and experimentally detected.
• Bright resonances were neither detected nor predicted by the theoretical model for such a system.
• We explained the narrow maximum previously observed in the degree of LIF polarization in earlier works.
• It was demonstrated that it is possible to describe nonlinear magneto-optical resonances in systems with large angular momenta over a wide range of experimental conditions with the theoretical model.
• As a result, theoretical modeling can serve as a tool for future investigations of systems with large angular momenta and for the development of practical applications based on them.