We experimentally observe coherent generation of a near-infrared optical field through three-wave mixing phenomenon in an atomic energy level scheme Rb85 atoms. This nonlinear process centro-symmetric thermally broadened system is made possible novel interaction between induced electric and magnetic dipoles. The two-photon three-photon coherence present our eliminates excited state decoherence. Thus, represents minimal decoherence which could be used to transfer quantum states...

We study phase-sensitive amplification of electromagnetically induced transparency in a warm $^{85}\mathrm{Rb}$ vapor wherein microwave driving field couples the two lower-energy states $\ensuremath{\Lambda}$ energy-level system thereby transforming into $\ensuremath{\Delta}$ system. Our theoretical description includes effects ground-state coherence decay and temperature effects. In particular, we demonstrate that driving-field-enhanced is robust against significant loss between ground...

We present an experimental study of a Δ system in room temperature, dilute sample 85Rb atoms. A the D2 manifold is formed by connecting two lower hyperfine energy levels Λ microwave drive field at 3.0357 GHz. show that when Rabi frequency exceeds optical probe field, three-wave mixing nonlinear interaction established. This changes enhanced transmission to deep absorption for relative phase difference π between all three fields. establish through our experiment and numerical simulation,...

We experimentally investigate and theoretically analyze the effect of microwave controlled atomic ground state coherence on phase-dependent amplification (PDA) an optical probe field. use three hyperfine levels in room temperature 85 Rb atoms, which are cyclically connected by two one electromagnetic show that a simultaneous fulfilment two-photon resonance condition creates three-photon leads to significantly higher 7.5 dB field with visibility 98.8 %. By selectively breaking using...

We report phase-sensitive amplification (PSA) of a near-infrared electromagnetic field using room-temperature 85Rb atoms possessing ground-state coherence. Our novelty is in achieving significant optical PSA by manipulating the intensity and phase frequency-separated microwave field. obtained inducing three-wave mixing nonlinear process utilising three-level cyclic scheme D1 manifold. achieve near-ideal with gain 7 dB over range 500 kHz bandwidth very low pump-field intensities depths. Such...

An experimental investigation of a Microwave Optical Double Resonance (MODR) phenomenon is carried out in four level N system 85Rb atoms, at room temperature. This consists closed three Λ subsystem irradiated with two optical fields and one microwave field. The MODR response investigated separate probe field which drives resonant transition from the ground states to fourth level. We find that, under two-photon resonance condition for fields, becomes function relative phase between beat...

Dual-cavity optoelectromechanical systems (OEMS) are those where two electromagnetic cavities connected by a common mechanical spring. These have been shown to facilitate high-fidelity quantum-state transfer from one cavity another. In this paper, we explicitly calculate the effect on fidelity of state when an additional spring is attached only cavities. Our quantitative estimates loss highlight sensitivity dual-cavity OEMS it couples modes. We show that can be used design effective switch...

We experimentally investigate near-infrared optical field generation through simultaneous three-wave mixing (TWM) and six-wave (SWM) processes in room-temperature 85Rb atoms. The nonlinear are induced using three hyperfine levels the D1 manifold, which cyclically interact with pump fields an idler microwave field. appearance of TWM SWM signals discrete frequency channels is made possible by breaking three-photon resonance condition. This gives rise to coherent population oscillations (CPO),...

We experimentally demonstrate binary phase-shift keying and multi-stage four phase shift of a microwave carrier its corresponding demodulation in the optical regime using room temperature Rb atoms. use cyclic three-level scheme 85Rb atoms to achieve this. The importance our is that cyclic, closed interaction atomic levels with electromagnetic fields makes system inherently sensitive field. This enables directly encode modulated digital signal field decode it as intensity modulation measure...

A cyclic atomic level scheme interacting with an optical and a microwave field is proposed for the generation group-delay control of few-photon pulses. Our analysis exploits hybrid second order-nonlinearity under conditions electromagnetically induced transparency to generate pulse. The generated pulse can be delayed or advanced through intensity absolute phase second-order-nonlinearity. Importantly, this handle on group delay number density-independent. thus ideally suited pulses using...

Chained correlation inequalities involving pairwise correlations of qubit observables in the equatorial plane are constructed based on positivity a sequence moment matrices. When jointly measurable set fuzzy POVMs is employed first measurement every pair sequential measurements, chained do not violate classical bound imposed by matrix positivity. We identify that incompatibility measurements only necessary, but sufficient, general, for violation inequality. On other hand, there exists...

The diversity order and coding gain are crucial for the performance of a multiple antenna communication system. It is known that space-time trellis codes (STTC) can be used to achieve these objectives. In particular, we use STTCs obtain large gains. Many attempts have been made construct which full-diversity good gains, though general method construction does not exist. Delay code (rate-1) full-diversity, any number transmit antennas signal set, but give gain. A product distance based delay...

Multi-level gaseous atomic systems showing electromagnetically induced transparency (EIT) phenomenon also exhibit low light intensity nonlinear optical phenomena. This is primarily due to the supression of linear susceptibility for probe during EIT. Therefore under EIT, interactions become appreciable even at very intensities. In particular, Kerr nonlinearity in N irradiated by three fields has been both experimentally and theoretically investigated. this paper, we report an all observation...

Abstract Coherent microwave-to-optical conversion is crucial for transferring quantum information generated in the microwave domain to optical frequencies, where propagation losses can be minimized. Coherent, atom-based transducers have shown rapid progress recent years. This paper reports an experimental demonstration of coherent that maps a signal large, tunable 550(30) MHz range frequencies using room-temperature 87 Rb atoms. The inhomogeneous Doppler broadening atomic vapor...

We perform balanced homodyne detection of the electromagnetic field in a single-mode tapered optical nanofiber surrounded by rubidium atoms magneto-optical trap. Resonant fluorescence into mode manifests itself as increased quantum noise quadratures. The autocorrelation function detector's output photocurrent exhibits exponential fall-off with decay time constant 26.3±0.6 ns, which is consistent theoretical expectation under our experimental conditions. To best knowledge, this first...

The concept of weak measurement and associated value amplification has sharpened our understanding the process in quantum mechanics. Recent experiments show that elastic scattering events resonance fluorescence can exhibit effect, by post-selecting a particular outcome. In this article, we theoretically analyse physics behind process. We that, general, interaction be derived from well-Known theory spontaneous emission put forth Wigner Weiskopff. Using regime fluorescence, helps segregating...

Weak measurements are a subset of measurement processes in quantum mechanics wherein the system, which is being measured, interacts very weakly with measuring apparatus. Measurement values observables undergoing weak interaction and their amplification concepts that have sharpened our understanding mechanics. Recent experiments show naturally occurring such as resonance fluorescence from excited states an atom can exhibit value effect. In this paper we theoretically analyze process elastic...

Weak measurements are a subset of measurement processes in quantum mechanics wherein the system which is being measured interacts very weakly with measuring apparatus. Measurement values observables undergoing weak interaction and their amplification, concepts that have sharpened our understanding mechanics. Recent experiments show naturally occurring such as resonance fluorescence from excited states an atom can exhibit value amplification effect. In this paper, we theoretically analyze...