Controlled light storage in a double lambda system

Abstract

It is shown theoretically that after light storing in a medium of four-level atoms it is possible to release a new pulse of a different frequency, the process being steered by another driving beam. It is also possible to store one pulse and to release two different ones, with their time separation and heights being controlled.Comment: 7 pages,3 figure

Two-color lasing in cold atoms

“…The energy of the atomic state |ν is given byhω ν ,h being the Planck's constant, μ 12 is the electric dipole moment of the |1 − |2 transition, and a † ω p andâ ω p are the creation and annihilation field operators, respectively, for a frequency mode ω p . The Rabi frequencies of the classical beams are denoted by 0 cj = cj e −iω 0 23 is the dipole moment of the |3 − |2 transition and E cj the corresponding electric field amplitude. The amplitudes of the quantum field operators read…”

“…For the storage of a general photonic qubit, i.e., a single photon in an arbitrary superposition of two different components, more sophisticated schemes are needed [16][17][18][19][20][21][22][23][24][25][26][27]. In quantum communication with photons, the logical qubits can be encoded in several ways, for example, via polarization, time bin, path, phase, photon number or even frequency encodings.…”

“…In quantum communication with photons, the logical qubits can be encoded in several ways, for example, via polarization, time bin, path, phase, photon number or even frequency encodings. In particular, several works have focused on the storage of photons with two frequency components using the EIT technique in resonant double-media [23][24][25][26][27][28][29][30][31]. Those proposals have been formulated mainly in the semiclassical regime.…”

“…In particular, only a specific combination of the two modes can be perfectly absorbed and recovered [24,36,37], whereas for an arbitrary two-frequency-mode input, part of the light will propagate transparently and part will be absorbed [24]. Nonetheless, it has been shown that the four-wave mixing processes arising in double-media, which make difficult the implementation of a suitable quantum memory, have interesting applications in frequency conversion of classical probe beams [36,38], single-photon frequency conversion preserving the quantum coherence [35], and in the possibility to combine or redistribute one or two previously stored frequency modes [23,27,37], even with different relative intensities [24]. An interesting situation is found when one of the two systems of the double-configuration is far detuned from the one photon resonance.…”

Electromagnetically induced transparency and storing of a pair of pulses of light

“…In particular it is possible to simultaneously propagate two optical pulses of different frequencies through a medium in the conditions of EIT. In our earlier paper [9] we have pointed out that one can stop one pulse and release a pulse of a different frequency or two different pulses. We have also mentioned that making the medium transparent simultaneously for two pulses is possible provided that the fields are in some special relation, which allows for an adiabatic evolution of the system.…”