Nonclassical effects such as squeezing, antibunching, and sub-Poissonian statistics of photons have been attracting attention in quantum optics over the last decade. Up to now most theoretical experimental investigations carried out exclusively time domain while neglecting spatial aspects by considering only one mode electromagnetic field. In many situations an approximation is well justified. There are, however, problems that do not allow principle a single-mode consideration. This case...

We study experimentally and numerically the temporal features of supercontinuum generated with a continuous-wave ytterbium-doped fiber laser. show that output is characterized by strong brief power fluctuations, i.e. so-called optical rogue waves. demonstrate these rare events appear disappear from nowhere result solitonic collisions.

We discuss the ultimate limit imposed by quantum fluctuations of light for resolution fine details in optical images. For this purpose, we extend domain classical analysis object reconstruction, or superresolution, terms prolate spheroidal function basis. derive expression reconstructed using an illumination full plane a multimode squeezed vacuum. show that gain is maximum when Shannon number imaging system close to unity.

We solve the problem of a laser with variable pumping statistics for any relative magnitude atomic- and cavity-decay constants, obtain different regime sub-Poissonian light generation. show that, even Poissonian pumping, noise in amplitude quadrature outside cavity can be reduced up to 50% below shot-noise level when polarization but not populations adiabatically eliminated. Maximum reduction this case is obtained lower decays much faster than upper one occurs at frequency given by...

We study a possibility of measuring the time-resolved second-order autocorrelation function one two beams generated in type-II parametric downconversion by means temporal magnification this beam, bringing its correlation time from picosecond to nanosecond scale, which can be resolved modern photodetectors. show that such measurement enables infer directly degree global coherence is linked simple relation number modes characterizing entanglement between beams. illustrate proposed method an...

We analyze a scheme consisting of an optical parametric amplifier and two imaging lenses. From off-axis input image such system creates quantum entangled output images, signal idler, symmetrical with respect to the axis scheme. In limit large amplification idler is twin one in sense that they display identical intensity fluctuations space-time.

We discuss a novel laser scheme in which N three-level atoms maintain full cooperativity stationary regime. The intensity I of radiation is proportional to ${\mathit{N}}^{2}$, the linewidth scales as 1/${\mathit{N}}^{2}$, and output fluctuations display up 100% squeezing at low frequencies. possibility simultaneously slowing down phase diffusion reducing makes this kind an attractive goal go for.

We introduce a new distance-based measure for the nonclassicality of states bosonic field, which outperforms existing such measures in several ways. define that purpose operator ordering sensitivity state evaluates to Renyi entropy its quasiprobabilities and oscillations Wigner function. Through sharp control on classical we obtain precise geometric image their location density matrix space allowing us nonclassicality. analyze link between this recently introduced quantum macroscopicity...

Induced coherence in parametric down-conversion between two coherently pumped nonlinear crystals that share a common idler mode can be used as an imaging technique. Based on the interference signal modes of crystals, image reconstructed. By obtaining expression for pattern is valid both low- and high-gain regimes down-conversion, we show how light emitted by controlled. With our comprehensive analysis provide deeper insight into recent discussions about application induced to different...

We report on the observation of broadband (40 THz) bright twin beams through high-gain parametric downconversion in an aperiodically poled lithium niobate crystal. The output photon number is shown to scale exponentially with pump power and not amplitude, as homogeneous crystals. Photon correlations frequency/temporal modes are assessed by spectral covariance measurements. By using sum-frequency generation surface a non-phase-matched crystal, we measure cross-correlation peak temporal width 90 fs.

We experimentally demonstrate the feasibility of a super-resolution technique based on eigenmode decomposition. This has been proposed theoretically but, to best our knowledge, not previously realized for optical imaging systems with circular apertures. use standard diffraction-limited 4f system apertures which radial eigenmodes are prolate spheroidal functions. For three original objects different content angular information we achieve 45%, 49%, and 89% improvement resolution over Rayleigh...

Using the space-time analogy, we compare performance of quantum temporal imaging with its classical counterpart. We consider a scheme, based on sum-frequency generation time lens, but our results can be applied to other schemes such as, for instance, four-wave mixing. Extending theory presented in previous publications, this paper take into account finite aperture system, characterized by pupil function. theory, obtain unitary transformation field from input output scheme and identify...

We study the Bloch-Messiah reduction of parametric down-conversion light in pulsed regime with a nondegenerate phase matching providing generation twin beams. find that this case every squeezing eigenvalue has multiplicity at least two. discuss problem ambiguity definition eigenmodes and develop two approaches to unique determination latter. First, we show modal functions can be tailored from Schmidt modes signal idler Alternatively, they found as solution an for associated Hermitian matrix....

Fourier-transform infrared spectroscopy (FTIR) is an indispensable analytical method that allows label-free identification of substances via fundamental molecular vibrations. However, the sensitivity FTIR often limited by low efficiency mid-infrared (MIR) photodetectors. SU(1,1) interferometry has previously enabled with undetected MIR photons spontaneous parametric down-conversion in low-parametric-gain regime, where number per mode much less than one and sensitive photodetectors are...

We propose a scheme for amplification of faint optical images with coherent light which preserves the signal-to-noise ratio in image. The consists ring-cavity parametric amplifier as an active element and two imaging lenses. This system can amplify either ``point by point,'' when small region is amplified at time, or narrow rings, depending on its operation; both cases it works image scanner. have evaluated inherent noise this has physical origin phenomenon spontaneous radiation. gives lower...

We propose a scheme that uses spatially multimode squeezed light, generated by means of traveling-wave optical parametric amplifier, with which faint phase object can be imaged sensitivity better than the shot-noise limit.

We demonstrate that modulation instability gain of time-localized signals (i.e., pulsed signals) depends strongly on the third-order dispersion, contrary to well-known case time-extended (cw signals). This surprising contribution an odd dispersion term this four-photon-mixing process is established analytically and confirmed by numerical simulations.

Most investigations of multipartite entanglement have been concerned with temporal modes the electromagnetic field and neglected its spatial structure. We present a simple model which allows us to generate tripartite between by parametric down-conversion two symmetrically tilted plane waves serving as pump. The characteristics this are investigated. also discuss generalization our scheme 2N+1 partite using 2N pump waves. Another interesting feature is possibility localization in just modes.

The entangled optical beams generated by pulsed parametric down-conversion provide enhanced sensitivity for interferometry and enable quantum computation, but their rich spatiotemporal modal structure lacks a simple analytic model. This study shows that in properly defined curvilinear coordinates combining the frequency transverse wave vector, functions have form thus can be rather easily analyzed measured. authors also show how degree of coupling manipulated varying pump pulse. approach...

Abstract Fourier-transform infrared spectroscopy (FTIR) is an indispensable analytical method that allows label-free identification of substances via fundamental molecular vibrations. However, traditional FTIR spectrometers require mid-infrared (MIR) elements, including low-efficiency MIR photodetectors. SU(1,1) interferometry has previously enabled with undetected photons spontaneous parametric down-conversion in the low-parametric-gain regime, where number per mode much less than one and...