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In this paper, we present a technically improved source of such rubidium resonant squeezed light. It uses a new pumping laser system and a technologically advanced locking scheme. To produce squeezed light, we use the proven technique of downconversion within a subthreshold OPO but with one distinct difference: our OPO is not pumped by a Ti:Sapphire laser, but by a diode laser system. This system...
Summary form only given. One of the major objectives in the field of quantum information is the realization of a memory for the quantum states of the light. The squeezed vacuum is required in order to test the quantum character of the memory i.e. its capability to store informations that rely on the quantum nature of the light. In order to generate the squeezed vacuum at a wavelength that is resonant...
We report on the generation of polarization squeezed states employing intense, ultrashort light pulses by a single pass method in photonic crystal fibers. We investigated the squeezing behavior near the zero-dispersion wavelength and in the anomalous dispersion regime by using two distinct fibers.
The latest results on the experimental generation of the position and momentum (x-p) entanglement for bright optical beams are presented. The measurements of the quantum correlations in the TEM10 mode with two optical parametric amplifiers are demonstrated. TEM10 quadrature entanglement is also demonstrated. Two position squeezed beams on a 50:50 beam splitter are used to demonstrate full x-p entanglement.
The novel aspect of this study is grounded on the fact that squeezing spectrum of a finite set of super-modes operators can be below the standard quantum limit, giving a clear image that the system is a highly quantum multi-mode system. In fact, not only the super-mode of minimum threshold is perfectly squeezed at threshold but, further, all the other super-modes have nonclassical character and are...
We develop experimental signatures for generalized macroscopic, mesoscopic and S-scopic quantum superpositions. We also examine the extent to which current experiments confirm their existence, and propose new measurements to further signify them. The size S of a quantum superposition (or pure state), with respect to the observable X, is defined as the maximum range in predictions for the observable...
Spin squeezed states can be used to improve the performance of atomic clocks and magnetometers. Recently, atom-light interaction of a similar type has also been used to demonstrate quantum memory and quantum teleportation between light and matter. Furthermore, this interaction facilitates studies in the field of controlled quantum dynamics.
The authors demonstrates that spatial quantum correlations are induced by multiple scattering of quadrature squeezed light through a random medium. As a consequence, light scattered along two different directions by the random medium will not be independent, but be correlated to an extent that can only be described by a quantum mechanical theory for multiple scattering. The spatial quantum correlation...
In this experiment we use periodically poled potassium titanyl phosphate (PPKTP) as the nonlinear crystal in an optical parametric oscillator (OPO) for the generation of squeezed light on the D1 line of rubidium which lies at 795 nm. Although OPOs have long been used as sources of squeezed light, the shorter wavelengths required for atomic interactions have always been a challenge due to a limited...
Continuous variable polarization states have attracted much attention due to their apparent applicability to quantum information networks. Polarization entanglement was presented by transformation of the well-known quadrature entanglement onto the polarization basis. The inseparability criteria as well as the EPR paradox criteria for Stokes operators were also demonstrated. In this paper the generation...
We study here a different scheme involving a large ensemble of Lambda-type atoms, a control field, and the field to be stored and show how to transfer with a nearly 100% efficiency a quantum state of light (squeezed vacuum) into the ground state coherence of a spin-polarized atomic cloud. We find the best transfer conditions between the two oscillators. The quantum states are well conserved in two...
This article proposes a model that provides important insights into the effect of inhomogeneities in atom-light interactions. This model is able to handle all different kinds of inhomogeneities. Moreover, it simulates the influence of imperfect temporal detector resolution.
We introduce a simple procedure - based on passive optical elements - to produce pure three-mode Gaussian states with arbitrary entanglement structure (upon availability of an initial single-mode squeezed state). We analyze in detail the properties of distributed entanglement, showing that the promiscuity of entanglement sharing is a feature peculiar to symmetric Gaussian states that survives even...
By using the supercell lattice method, we investigate the influence of the squeezing lattice on the birefringence characteristics of photonic crystal fibers (PCFs). We first define the concept of squeezing ratio and then present a model, with which several types of PCFs are simulated. Simulation results show that the squeezing of PCFs' lattice with the uniform air holes in the cladding can break the...
Based on previously developed accurate and efficient Muller boundary integral equations (MBIEs) algorithms, we review known and explore news ways of controlled manipulation of whispering-gallery modes in meso-scale hybrid cavity structures, enabling fine tuning of their optical spectra and emission characteristics. Proposed novel structures include photonic molecules (PMs) composed of both identical...
We observed 7.2 dB squeezing of continuous-wave light at 860 nm with a periodically-poled KTiOPO4 crystal in an optical parametric oscillator. The squeezing level was obtained as the LO phase was locked.
An experiment is proposed for performing adaptive phase measurements on a continuous squeezed beam such that the variance is below the standard quantum limit. The theory takes into account many issues ignored in previous work.
Multimode operation of an optical parametric oscillator operating below threshold is calculated. We show that maximal squeezing can be obtained at high frequency even in the presence of seed laser noise and cavity length fluctuations.
We have generated squeezed vacuum in optical telecommunication band by a single-pass parametric amplification in periodically poled lithium niobate. The measured noise reduction was 3.1 dB below the shot-noise level.
The following topics are dealt with: The following topics are dealt with: exotic nonlinear optical phenomena; periodically poled materials; nonlinear processes in microstructured fiber; grating feedback lasers; instrumentation and diagnostics; optical frequency metrology; mode-locked sources; cellular sensing; molecular sensing; terahertz plasmons; metamaterials; optical signal processing; waveguides...
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