Quantum manipulation of two-color stationary light: Quantum wavelength conversion

Abstract

We present a quantum manipulation of a traveling light pulse using double atomic coherence for two-color stationary light and quantum frequency conversion. The quantum frequency conversion rate of the traveling light achieved by the two-color stationary light phenomenon is near unity. We theoretically discuss the two-color stationary light for the frequency conversion process in terms of pulse area, energy transfer and propagation directions. The resulting process may apply the coherent interactions of a weak field to nonlinear quantum optics such as quantum nondemolition measurement.PACS number(s): 42.65.Ky, 32.80, 03.67.Dd. IntroductionCoherent interactions have been intensively studied for the last several decades in nonlinear optics to utilize weak light for enhanced light-matter interactions [1]. Because nonlinear optics should intrinsically rely on strong field interactions, using a weak field light has been a fundamental limitation in pump laser intensity [2]. Thus, coherent interactions have drawn much attention to the weak-field limited nonlinear optics. The weak field nonlinear interactions are mostly important to quantum information sciences that need repeated non-destructive measurements of physical observables and deterministic quantum switching for quantum processing [3]. So far, an optical cavity has been an essential tool to control the weak quantum light interacting with an optical medium [4]. However, applying the optical cavity to the traveling light has been a major drawback in operational bandwidth due to the trade-off between the trapping time and the transparency of the cavity.Electromagnetically induced transparency (EIT) [5] has been studied for the last fifteen years to alleviate the intensity threshold in nonlinear optics and has been successfully applied to quantum optics by utilizing nonabsorption resonance and dispersion control of an optical medium in a traveling light scheme [6][7][8][9][10]. Actually the dispersion control of EIT is of great benefit to us when using the traveling light for deterministic quantum coherent control to decelerate or even completely stop the light pulses. With a simple modification of the EIT scheme, one can obtain a giant phase shift [11], where the phase shift itself has been a major goal in nonlinear optics for switching applications as well as in quantum optics for generation of Schrodinger's cat states [12]. Here, it should be noted that the π-phase shift is an essential acquirement for the optical switching based on Mach-Zehnder interferometer and quantum superposition. The giant phase-shift in a weak field limit has been studied using stationary light phenomenon [13]. Recently, Lukin et al. demonstrated photon trapping in a hot atomic gas using identical counterpropagating control fields resulting in standing-wave grating [14]. The photon trapping as a stationary light gives a predominant property to nonlinear quantum optics particularly when an optical medium is spatially limited and highly absorptive. The stationary light phenomenon can replace...

Dark-state polaritons for multicomponent and stationary light fields

“…Recently it has been shown that the simultaneous presence of two counter-propagating control fields of comparable strength can lead to a quasi-stationary pattern of slow light consisting of two counter-propagating probe field components [7,8,9,10]. Such stationary light pulses hold particular interest as examples of efficient nonlinear optical processes.…”

Photonic-band-gap properties for two-component slow light

“…EIT allows to transmit a resonant probe beam through an otherwise opaque atomic medium coherently driven by a control laser field and forms the basis of many interesting applications as e.g. creating stationary excitations of light [33][34][35][36][37] in more complex double Λ schemes as shown in Fig. 1b, Bose-Einstein condensation of photons [36,38], or artificial magnetic fields [37,39] for photons.…”

“…Employing two pairs of counterpropagating beams involves two atomic coherences leading to the SSL. By applying the secular approximation [33,34], the SSL has been shown to obey an effective 1D Dirac equation [45]. This approximation is however only justified in hot atomic gases [8,46], because it neglects all higher wave-vector components of the atomic coherence produced by the counterpropagating beams driving the same transition.…”

Dynamical observations of self-stabilizing stationary light

“…Later analysis showed that counter-propagating control fields of very different frequencies can also give rise to SL. The explanation is that shape-preserving EIT propagation in both directions can add up to prevent propagation [23,24]. In fact, true standing wave control fields can cause unwanted coupling between counter-propagating fields and additional decay of the SL pulse [25,26,27,28].…”