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Semi-classical Theory of Atom-Field Interaction
Published in Pradip Narayan Ghosh, Laser Physics and Spectroscopy, 2018
Thus, the atom oscillates between the levels a and b with the time period T and frequency Ω. This phenomenon is called Rabi flopping. A pulse of duration πΩ is known as the π pulse. This pi-pulse will take the atom from the lower state to the upper sate and the system will not revert back, if there is no spontaneous emission. This pulse changes the phase of the system by π. In presence of a continuous wave laser the system will flip back and forth with Rabi frequency.
R
Published in Philip A. Laplante, Comprehensive Dictionary of Electrical Engineering, 2018
Rabi frequency the characteristic coupling strength between a near-resonant electromagnetic field and two states of a quantum mechanical system. For example, the Rabi frequency of an electric dipole allowed transition is equal to µE/hbar, where µ is the electric dipole moment and E is the maximum electric field amplitude. In a strongly driven 2-level system, the Rabi frequency is equal to the rate at which population oscillates between the ground and excited states.
Propagation and Energy Transfer
Published in James D. Taylor, Introduction to Ultra-Wideband Radar Systems, 2020
Robert Roussel-Dupré, Terence W. Barrett
The rate at which transitions are coherently induced between two atomic levels is known as the Rabi frequency. At this frequency, there is a signal-and-medium resonance. A coherent light wave will exactly invert a ground state atom if the pulse is a “π pulse” so that () κE(t)=π,
Cavity-mediated collective laser-cooling of a non-interacting atomic gas inside an asymmetric trap to very low temperatures
Published in Journal of Modern Optics, 2018
Oleg Kim, Prasenjit Deb, Almut Beige
Moreover, we need to find a way to realise the system Hamiltonian in Equation (1), at least to a very good approximation. To do so, we proceed as usual in cavity-mediated laser cooling [23–28]. During each cooling stage, a cooling laser with Rabi frequency is applied. The cooling laser should enter the resonator from the side, as illustrated in Figure 2. Moreover, the laser frequency should coincide with the atomic transition frequency but should be below the cavity photon frequency . As we shall see below, best results are obtained when the cavity-atom detuning equal the phonon frequency of the trapped particles,
Time-dependent state populations with and without the rotating wave approximation: a model-based study
Published in Journal of Modern Optics, 2019
Panels C and D of Figure 2 show the same quantities as panels A and B, but for the resonant coupling of the two states ( 0.12663 a.u.). Approaching the resonance leads to a decreased Rabi frequency and a total population inversion of the states. In spite of the larger population transfer, no visible differences occur between the RWA and exact populations (Figure 2c). Indeed, as shown in Figure 2(d) the differences are reduced by approximately 1 order of magnitude compared to the a.u. detuned situation, and a significantly slower increase of the population difference is found justifying the application of the RWA.
Sub-recoil-limit laser cooling via interacting dark-state resonances
Published in Journal of Modern Optics, 2019
Vase Moeini, Seyedeh Hamideh Kazemi, Mohammad Mahmoudi
The considered atomic system is composed of four-level atoms which are coupled by laser fields and restricted to move along the x direction, according to the scheme depicted in Figures 1 and 2(a). A strong coherent field with frequency is applied to transition with Rabi frequency . A weak coupling field with Rabi frequency and frequency couples to the transition . Moreover, transition is driven by a weak probe field with frequency and Rabi frequency . The spontaneous decay rates on the dipole-allowed transitions are denoted by , , and . We also define as the energies of the involved states, and the transition frequencies are denoted by . Moreover, laser field detuning with respect to the atomic transition frequency is given by . Noting that the general expression for a Rabi frequency is defined as with and being the atomic dipole moment of the corresponding transition and amplitude of the field, respectively. This system can be realized in mercury with the probe transition at 253.7 nm (see Figure 2(b) for more details).