GROUND-STATE HANLE RESONANCES IN CESIUM VAPOR CONFINED IN NANOSCOPIC THIN CELL (progress report)

Transcription

1 GROUND-STATE HANLE RESONANCES IN CESIUM VAPOR (progress report) M. Auzinsh, K. Blush, Riga, Latvia C. Andreeva, S. Cartaleva, L. Petrov Institute of Electronics, Bulgarian Academy of Sciences Sofia, Bulgaria D. Sarkisyan, T. Varzhapetyan Institute for Physical Research, National Academy of Sciences of Armenia Ashtarak-2, Armenia 2 Tuesday, August 2, 2-1-

2 GROUND-STATE HANLE RESONANCES Creation of Zeeman coherences by laser radiation between the magnetic sublevels of the hyperfine states of an atom Destruction of Zeeman coherences by an external magnetic field 2 Tuesday, August 2, 2-2-

3 Creation and destruction of atomic coherence J e =1 z B σ σ + E σ y J g =1 x σ + M=-1 M= M=+1 2 Tuesday, August 2, 2-3-

4 What is nanoscopic (ETC) cells? Cs ETC Transmitted light k d = 1 1 nm Laser radiation 2 Tuesday, August 2, 2-4-

5 What is nanoscopic cell (ETC)? L= - 3 nm Glue YAG crystal windows Al 2 O 3 strip Glue Sapphire tube (side-arm) Rb Cs Cs ETC 2 Tuesday, August 2, 2 --

6 What is ETC? 2 Tuesday, August 2, 2-6-

7 Laser What is ETC? An atom 2 Tuesday, August 2, 2-7-

8 What is ETC? D. Sarkisyan, A. Papoyan, T. Varzhapatyan, K. Blushs, M. Auzinsh, J. Opt. Soc. Am. B/Vol. 22, 2, Tuesday, August 2, 2-8-

9 Nobel prize in physics 1982 Polarization spectroscopy Saturated interference spectroscopy Spectroscopy of polarization labeling 2 Tuesday, August 2, 2-9-

10 Experimental set-up ECDL BS BS SA-reference signal BS Cs cell Probe beam PD PC Pump beam M M L Helmholtz coils Lock-in M k T2 ETC Cs source T1 Oven PD Transmission signal M PD Fabry-Perot Interferometer 2 Tuesday, August 2, 2-1-

11 Cs - where do we work? 82 nm (D 2 ) 133 Cs F 6P e = 3/2 22 MHz F e =4 21 MHz F e =3 11 MHz F e =2 6S 1/2 F g =4 a) ETC transmission [a. u.] d = λ b) a) b) Reference SA signal [a.u.] GHz F g = Laser frequency detuning [MHz] 2 Tuesday, August 2, 2-11-

12 Results transition Fg = 4 Fe = Resonance profile [a.u.] ,2 mw / cm 2 Resonance profile [a.u.] ,7 mw / cm 2 Resonance profile [a.u.] ,3 mw / cm Tuesday, August 2, 2-12-

13 F g = 4 F g = 3 fluorescence (a.u.) ν 4 ν 3 a I L = 3 mw/cm ν 4 ν 3 c Cs Cs - Nonlinear Hanle effect in ordinary cells b.9.8 d F g = 4 F g = 3 fluorescence (a.u.) ν 4 ν 3 I L = 6 mw/cm ν 4 ν magnetic field (Gauss) magnetic field (Gauss) π k B σ + k B Papoyan, A.V., M. Auzinsh, and K. Bergmann, European Physical Journal D, (1): p Tuesday, August 2, 2-13-

14 Results transition Fg = 4 Fe = Resonance profile [a.u.] ,2 mw / cm 2 Resonance profile [a.u.] ,7 mw / cm 2 Resonance profile [a.u.] ,3 mw / cm Tuesday, August 2, 2-14-

15 Results transition Fg = 4 Fe = ,7 mw / cm ,7 mw / cm 2 Transmission [a.u.] mw / cm Transmission [a.u.] Transmission [a.u.] Tuesday, August 2, 2-1-

16 Hanle experiment Cs ETC F g = 4 -> F e = transition. Transmitted light Transmission [a.u.] 33, Gauss ETC resonance k Laser radiation B 1,2 Gauss long cell resonance M agnetic field [Gauss] 2 Tuesday, August 2, 2-16-

17 Theory Optical Bloch (Liouville) equations 2 Tuesday, August 2, 2-17-

18 Theory Rate equations for Zeeman coherences Validity: Broad line excitation or Stationary exctation at anylinewidth Kaspar Blushs, Marcis Auzinsh 2 Tuesday, August 2, 2-18-

19 B F e 1. In a magnetic field m and µ remain good quantum numbers F g 2. F states are mixed by a magnetic field 2 Tuesday, August 2, 2-19-

20 ΓΜ Μ' = Γ Cs 1 1+ E 4 Supersīkstruktūras enerģija, MHz Energy, MHz MM F 4 3 ' Γ Cs, 6 2 P 3/ Magnetic Magnētiskais field, lauks, G 2 Tuesday, August 2, 2-2-

21 Results transitions Fg Fg = = 3 3 Fe Fe =2,3,4 =? Fig.A (1) ETC-transm (3) ETC: MF= - (1) SA: MF= - (2) ETC: MF=16G - (3) SA: MF=16G - (4) tr. 3-3 tr tr. (2) -8-1 (4) SA cell-transm Laser 4 frequency 2 Tuesday, August 2, 2-21-

22 Results transition Fg = 3 Fe = ETC-transm ETC: MF= - (1) SA: MF= - (2) ETC: MF=16G - (3) SA: MF=16G - (4) (1) (3) -2-4 (2) 3-2 transition (4) SA cell-transm -6-8 Laser frequency Tuesday, August 2, 2-22-

23 Results transition Fg = 3 Fe = 3 8 (3) (1) ETC -transm (2) 3-3 transition ETC: MF= - (1) SA: MF= - (2) ETC: MF=1,7A - (3) SA: MF=1,7A - (4) SA cell-transm -6-8 (4) Laser frequency 3 2 Tuesday, August 2, 2-23-

24 Results transition Fg = 3 Fe = 4 2 ETC-transm (1) ETC: MF= - (1) SA: MF= - (2) ETC: MF=1,7A - (3) SA: MF=1,7A - (4) -2 (2) 3-4 transition SA cell-transm -4-6 (4) (3) 4 Laser frequency 2 Tuesday, August 2, 2-24-

25 Results transition Fg = 4 Fe = Resonance profile [a.u.] ,2 mw / cm 2 Resonance profile [a.u.] ,7 mw / cm 2 Resonance profile [a.u.] ,3 mw / cm Resonance profile [a.u.] Rabi frequency: 2 MHz Resonance profile [a.u.] Rabi frequency: MHz Resonance profile [a.u.] Rabi frequency: 7 MHz 2 Tuesday, August 2, 2-2-

26 Results transition Fg = 4 Fe = ,7 mw / cm ,7 mw / cm 2 Transmission [a.u.] mw / cm Transmission [a.u.] Transmission [a.u.] Rabi frequency: MHz 14 Rabi frequency: 12 MHz 14 Rabi frequency: 13 MHz Resonance profile [a.u.] Resonance profile [a.u.] Resonance profile [a.u.] Tuesday, August 2, 2-26-

27 Rabi frequency vs. light intensity 2 F g = 4 -> F e = 4 transition 2 F g = 4 -> F e = transition (Rabi frequency, MHz) 2, x1 1 1 (Rabi frequency, MHz) 2, x Intensity [mw / cm] Intensity [ mw / cm 2 ] Theoretical prediction solid line Experimentally measured values - dots 2 Tuesday, August 2, 2-27-

28 Cs - where do we work? 82 nm (D 2 ) 133 Cs F e = 6P 22 MHz 3/2 F e =4 21 MHzF e =3 11 MHz F e =2 a) ETC transmission [a. u.] d = λ b) a) b) Reference SA signal [a.u.] 6S 1/ GHz F g =4 F g = Laser frequency detuning [MHz] 2 Tuesday, August 2, 2-28-

29 Conclusions 1. For the first time observed the nonlinear Hanle effect (creation and destruction of Zeeman coherences in the ground state of Cs atoms) in the ETC; 2. For all types of atomic transitions dark resonances were observed in the ETC cell without buffer gas; 3. Phenomenological model of atom wall interaction proposed that can explain appearance of dark resonances in cases when bright resonances were expected; 2 Tuesday, August 2, 2-29-

30 Tigran Varzhapetyan Christina Andreeva Lubomir Petrov People Stefka Cartaleva Kaspars Blushs 2 Tuesday, August 2, 2-3-

31 Funding NSF of Bulgaria: grant F- 144/4 Grant 2/2 under French- Bulgarian, Rila collaboration Latvian Science Foundation, Grant Nr. 812 EC FP PROJECT # G1MA-CT INSTITUTE OF ATOMIC PHYSICS AND SPECTROSCOPY Centre of Excellence for Basic Research in Nanoscale Physics and Applications European Social Foundation project for the 2 Tuesday, August 2, 2-31-