Pulse propagation, population transfer, and light storage in five-level media

Abstract

We consider adiabatic interaction of five-level atomic systems and their media with four short laser pulses under the condition of all two-photon detunings being zero. We derive analytical expressions for eigenvalues of the system's Hamiltonian and determine conditions of adiabaticity for both the atom and the medium. We analyze, in detail, the system's behavior when the eigenvalue with nonvanishing energy is realized. As distinct from the usual dark state of a five-level system (corresponding to zero eigenvalue), which is a superposition of three states, in our case the superposition of four states does work. We demonstrate that this seemingly unfavorable case nevertheless completely imitates a three-level system not only for a single atom but also in the medium, since the propagation equations are also split into those for three-and two-level media separately. We show that, under certain conditions, all the coherent effects observed in three-level media, such as population transfer, light slowing, light storage, and so on, may efficiently be realized in five-level media. This has an important advantage that the light storage can be performed twice in the same medium; i.e., the second pulse can be stored without retrieving the first one, and then the two pulses can be retrieved in any desired sequence.

Pulse propagation in the slow and stopped light regime

“…Our formulation can be generalized for a weak longitudinal grating, by adopting the approach in [60][61][62][63]. The formulation will also be trivially valid for pulse propagation in (uniform) atomic media [2,3,30,31] and quantum models of stopped light [26][27][28], which as noted, were so far usually modelled with rather simplistic models in which second-order and higher-order dispersion effects were neglected.…”

“…In recent decades, slow light was demonstrated also at optical frequencies [2][3][4][5][6][7], and it was even shown that the light can nearly be brought to a standstill ("stopped light") [8][9][10]. As a result, various potential applications emerged, including in particular optical memory in optical communication systems [6,[11][12][13], nonlinear optics [7,[14][15][16][17][18][19][20][21], Brillouin scattering [22,23], and more recently, quantum computing [10,[24][25][26][27][28][29], e.g., based on electromagnetic induced transparency [2,3,8,9,[30][31][32]; Additional potential applications are tissue imaging [33], sensing [34], low threshold lasing [35][36][37][38][39], photochemistry [40,41] and even table...…”

“…In many studies (especially, in the context of atomic vapours), pulse propagation in the slow light regime was studied via a somewhat phenomenological transport equation for the pulse envelope [27][28][29], i.e., neglecting second-and higher-order dispersion terms. More accurate models (usually, for pulse propagation in waveguides or photonic crystals) were based on envelope equations like the nonlinear Schrödinger equation, see Section 2 and [53].…”

Catastrophic breakdown of the Caves model for quantum noise in some phase-insensitive linear amplifiers or attenuators based on atomic systems

“…A similar five-level system has been studied in Refs. [24] and [25], although under different conditions. State 4 decays to states 1 and 2 at rates !…”

“…A similar five-level system has been studied in Refs. [24] and [25] To see the behavior of the system at the center of the dip more transparently, it is instructive to consider a reduced system produced via adiabatic elimination of states 4 and 5 (this approximation is for illustration only, and will not be made in the ME analysis as well as the semiclassical analysis to follow in this section). The system is then reduced to a configuration similar to the Λ-type EIT system as shown in Fig.…”