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Title: Coherent population trapping in a crystalline solid at room temperature

Abstract

Observation of coherent population trapping (CPT) at ground-state Zeeman sublevels of Cr{sup 3+} ion in ruby at room temperature is reported. A mechanism of CPT, not owing to optical pumping, is revealed in a situation when the optical pulse duration is shorter than the population decay time from the excited optical state.

Authors:
 [1]
  1. Department of Physics and Institute for Quantum Studies, Texas A and M University, College Station, Texas 77843-4242 (United States)
Publication Date:
OSTI Identifier:
20786434
Resource Type:
Journal Article
Resource Relation:
Journal Name: Physical Review. A; Journal Volume: 72; Journal Issue: 5; Other Information: DOI: 10.1103/PhysRevA.72.051801; (c) 2005 The American Physical Society; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
74 ATOMIC AND MOLECULAR PHYSICS; CHROMIUM; CHROMIUM IONS; DECAY; GROUND STATES; OPACITY; OPTICAL PUMPING; OPTICS; POPULATIONS; PULSES; RADIATION PRESSURE; RUBY; SOLIDS; TEMPERATURE RANGE 0273-0400 K; TRAPPING; ZEEMAN EFFECT

Citation Formats

Kolesov, Roman. Coherent population trapping in a crystalline solid at room temperature. United States: N. p., 2005. Web. doi:10.1103/PHYSREVA.72.0.
Kolesov, Roman. Coherent population trapping in a crystalline solid at room temperature. United States. doi:10.1103/PHYSREVA.72.0.
Kolesov, Roman. Tue . "Coherent population trapping in a crystalline solid at room temperature". United States. doi:10.1103/PHYSREVA.72.0.
@article{osti_20786434,
title = {Coherent population trapping in a crystalline solid at room temperature},
author = {Kolesov, Roman},
abstractNote = {Observation of coherent population trapping (CPT) at ground-state Zeeman sublevels of Cr{sup 3+} ion in ruby at room temperature is reported. A mechanism of CPT, not owing to optical pumping, is revealed in a situation when the optical pulse duration is shorter than the population decay time from the excited optical state.},
doi = {10.1103/PHYSREVA.72.0},
journal = {Physical Review. A},
number = 5,
volume = 72,
place = {United States},
year = {Tue Nov 15 00:00:00 EST 2005},
month = {Tue Nov 15 00:00:00 EST 2005}
}
  • Coherent population trapping (CPT) in a three-level atomic medium pumped by two subsequent short optical pulses is considered under the condition of negligible population decay from the excited optical state. It is shown that the amount of atomic population transferred to the excited state by the combined action of the pulses strongly depends on the phase of the ground-state coherence excited by the first pulse at the arrival time of the second pulse. Oscillatory behavior of optical excitation efficiency on the time delay between the pulses is predicted. It is also shown that saturating optical pulses can produce population inversionmore » in a resonantly pumped quasi-two-level system. A class of solid materials in which the predicted phenomena can be observed at room temperature is found. It includes some rare-earth and transition-metal doped dielectric crystals where Orbach relaxation between ground-state Zeeman states is suppressed: ruby, alexandrite, and several others. On the basis of the theoretical predictions, experimental observation of Ramsey fringes in CPT spectrum of ruby is reported.« less
  • We study how coherent Stokes and anti-Stokes Raman scattering influence coherent population trapping. In an experiment using an atomic sodium vapor cell we observe induced transparency, induced absorption, and gain features, all of subnatural linewidth. The electromagnetically induced resonance is a peak or a dip depending on which side of the optical transition the fields are tuned to, and thus whether coherent anti-Stokes Raman scattering or coherent Stokes Raman scattering is the dominant process.
  • We present a new laser-cooling scheme based on velocity-selective optical pumping of atoms into a nonabsorbing coherent superposition of states. This method has allowed us to achieve transverse cooling of metastable /sup 4/He atoms to a temperature of 2 ..mu..K, lower than both the usual Doppler cooling limit (23 ..mu..K) and the one-photon recoil (4 ..mu..K). The corresponding de Broglie wavelength (1.4 ..mu..m) is larger than the atomic transition optical wavelength.
  • Coherent trapping of atomic population in sodium induced by two-frequency laser light has been studied by using a charge exchange reaction for probing the upper level population. When the two-photon resonance condition occurs, the signal due to electron capture from excited Na[sup *](3[ital p]) atoms by He[sup 2+] projectile ions exhibits the characteristic black resonance'' dip, indicating (by nonoptical means) that the fraction of Na atoms in the excited state actually drops to zero.
  • The effect of coherent population trapping in the resonance 1{yields}0 system submitted to a saturating field of the elliptically polarized wave is theoretically studied using the irreducible tensor-operator technique. Exact analytic expressions for the field-induced high-order multipolar moment (orientation, alignment) are obtained, and it is shown that both nonuniform population and Zeeman coherence arise for the magnetic sublevels of the system. Numerical estimates are given and the conditions are revealed under which the effect of coherent population trapping occurs in the system. 21 refs.