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Title: Measurement of excited-state lifetime using two-pulse photon echoes in rubidium vapor

Abstract

We report a measurement of the 5P{sub 3/2} excited-state lifetime using two-pulse photon echoes in Rb vapor. The measurement is precise to {approx}1% and agrees with the best measurement of atomic lifetime in Rb. The results suggest that a measurement precise to {approx}0.25% is possible through additional data acquisition and study of systematic effects. The experiment relies on short optical pulses generated from a cw laser using acousto-optic modulators. The excitation pulses are on resonance with the F=3{yields}F{sup '}=4 transition in {sup 85}Rb or the F=2{yields}F{sup '}=3 transition in {sup 87}Rb. The resulting photon echo signal is detected using a heterodyne detection technique. The excited-state lifetime is determined by measuring the exponential decay of the echo intensity as a function of the time between the excitation pulses. We also present a study of the echo intensity as a function of excitation pulse area and compare the results to simulations based on optical Bloch equations. The simulations include the effects of spontaneous emission as well as spatial and temporal variations of the intensities of excitation pulses.

Authors:
; ; ; ; ; ;  [1]
  1. Department of Physics and Astronomy, York University, Toronto Ontario M3J 1P3 (Canada)
Publication Date:
OSTI Identifier:
20929630
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of the Optical Society of America. Part B, Optical Physics; Journal Volume: 24; Journal Issue: 3; Other Information: DOI: 10.1364/JOSAB.24.000671; (c) 2007 Optical Society of America; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; BLOCH EQUATIONS; DATA ACQUISITION; EMISSION; EXCITATION; EXCITED STATES; LASERS; LIFETIME; MODULATION; MULTI-PHOTON PROCESSES; PHOTON-ATOM COLLISIONS; PHOTONS; PULSES; RESONANCE; RUBIDIUM; RUBIDIUM 85; RUBIDIUM 87; SIGNALS; SIMULATION; TIME DEPENDENCE; VAPORS

Citation Formats

Rotberg, E. A., Barrett, B., Beattie, S., Chudasama, S., Weel, M., Chan, I., and Kumarakrishnan, A.. Measurement of excited-state lifetime using two-pulse photon echoes in rubidium vapor. United States: N. p., 2007. Web. doi:10.1364/JOSAB.24.000671.
Rotberg, E. A., Barrett, B., Beattie, S., Chudasama, S., Weel, M., Chan, I., & Kumarakrishnan, A.. Measurement of excited-state lifetime using two-pulse photon echoes in rubidium vapor. United States. doi:10.1364/JOSAB.24.000671.
Rotberg, E. A., Barrett, B., Beattie, S., Chudasama, S., Weel, M., Chan, I., and Kumarakrishnan, A.. Thu . "Measurement of excited-state lifetime using two-pulse photon echoes in rubidium vapor". United States. doi:10.1364/JOSAB.24.000671.
@article{osti_20929630,
title = {Measurement of excited-state lifetime using two-pulse photon echoes in rubidium vapor},
author = {Rotberg, E. A. and Barrett, B. and Beattie, S. and Chudasama, S. and Weel, M. and Chan, I. and Kumarakrishnan, A.},
abstractNote = {We report a measurement of the 5P{sub 3/2} excited-state lifetime using two-pulse photon echoes in Rb vapor. The measurement is precise to {approx}1% and agrees with the best measurement of atomic lifetime in Rb. The results suggest that a measurement precise to {approx}0.25% is possible through additional data acquisition and study of systematic effects. The experiment relies on short optical pulses generated from a cw laser using acousto-optic modulators. The excitation pulses are on resonance with the F=3{yields}F{sup '}=4 transition in {sup 85}Rb or the F=2{yields}F{sup '}=3 transition in {sup 87}Rb. The resulting photon echo signal is detected using a heterodyne detection technique. The excited-state lifetime is determined by measuring the exponential decay of the echo intensity as a function of the time between the excitation pulses. We also present a study of the echo intensity as a function of excitation pulse area and compare the results to simulations based on optical Bloch equations. The simulations include the effects of spontaneous emission as well as spatial and temporal variations of the intensities of excitation pulses.},
doi = {10.1364/JOSAB.24.000671},
journal = {Journal of the Optical Society of America. Part B, Optical Physics},
number = 3,
volume = 24,
place = {United States},
year = {Thu Mar 15 00:00:00 EDT 2007},
month = {Thu Mar 15 00:00:00 EDT 2007}
}
  • The collisional relaxation cross section of the excited 3P-3D superposition state of Na with Ar is measured. A photon echo from the 3P-3D transition in Na vapor is spontaneously emitted at lambda = 8183 A after excitation of the 3D state and for the 3P/sub 3//sub ///sub 2/ state. (AIP)
  • A two-color photon echo peak shift measurement to probe the electronic coupling strength in molecular complexes is proposed. Exciton transfer between the electronic eigenstates is neglected and the baths associated with each monomer are assumed to be independent of each other. Within this simplified model, we derive a useful relation which can be used to estimate the electronic coupling strength via a combination of a normal one-color and the present two-color peak shift measurements. A simulation based on the cumulant expansion technique illustrates the validity of our suggestion. {copyright} {ital 1999 American Institute of Physics.}
  • We report a precision measurement of the cesium 6P{sub 3/2} excited-state lifetime. Two collimated, counterpropagating thermal Cs beams cross perpendicularly to femtosecond pulsed laser beams. High timing accuracy is achieved from having excitation and ionization laser pulses which originate from the same mode-locked laser. Using pulse selection we vary the separation in time between excitation and ionization laser pulses while counting the ions produced. We obtain a Cs 6P{sub 3/2} lifetime of 30.460(38) ns, which is a factor of two improvement from previous measurements and with an uncertainty of 0.12%, is one of the most accurate lifetime measurements on record.
  • The absolute two-photon excitation cross section for the H/sub 2/ E,F /sup 1/..sigma../sub g/ (v' = 6)left-arrowX/sup 1/..sigma../sub g/ (v'' = 0) Q(1) transition at 193 nm has been measured by observing the E,F /sup 1/..sigma../sub g//sup +/ (v' = 6)->B /sup 1/..sigma../sub u//sup +/ (v'' = 0) fluorescence at /similar to/750 nm. The measured integrated two-photon excitation cross section, (2.0 +- 0.9) x 10/sup -36/ cm/sup 4/, is in good agreement with the theoretical value of 2.8 x 10/sup -36/ cm/sup 4/, which is obtained from previously published calculations (Huo and Jaffe, Chem. Phys. Lett. 101, 463 (1983)). Themore » absolute cross section for photoabsorption by the E,F state at 355 and 193 nm was also measured by monitoring the depletion of the 750-nm fluorescence caused by a second laser. The measured cross sections for photoabsorption by the E,F (v = 6) state are (9.7 +- 2.4) x 10/sup -18/ cm/sup 2/ at 355 nm and (6.4 +- 1.3) x 10/sup -18/ cm/sup 2/ at 193 nm. Comparison with theoretical estimates (Cohn, J. Chem. Phys. 57, 2456 (1972)) of the direct photoionization cross section of this state (8.5 x 10/sup -18/ cm/sup 2/ at 355 nm and 3.2 x 10/sup -18/ cm/sup 2/ at 193 nm) suggests that other processes may contribute to the photoabsorption.« less
  • The article gives the results of a study of the effect of He buffer gas on nonlinear processes during two-photon excitation of rubidium vapor. In addition to four-photon parametric luminescence and a stimulated four-photon parametric process, lines of two-photon decay and stimulated electronic Raman scattering, not previously observed in rubidium vapor, have been obtained. The dependences of these processes on the pressure of the buffer gas and on the frequency of the exciting radiation are investigated and discussed.