Showing papers in "Journal of Modern Optics in 2018"
TL;DR: The main aim of as mentioned in this paper is to study the coupled sine-Gordon equations in nonlinear optics, which describe the propagation of an optical pulse in a fiber-optic waveguide.
Abstract: The main aim of this article is studying the coupled sine-Gordon equations in nonlinear optics, which describe the propagation of an optical pulse in fibre waveguide. New exact solutions of the cou...
92 citations
TL;DR: The ability to determine the joint spectral properties of photon pairs produced by the processes of spontaneous parametric downconversion (SPDC) and spontaneous four-wave mixing (SFWM) is crucial for determining the joint spectra as mentioned in this paper.
Abstract: The ability to determine the joint spectral properties of photon pairs produced by the processes of spontaneous parametric downconversion (SPDC) and spontaneous four-wave mixing (SFWM) is crucial f...
75 citations
TL;DR: In this article, a highly sensitive refractive index sensor based on an integrated hybrid plasmonic waveguide (HPWG) and a Metal-Insulator-Metal (M-I-M) micro-ring resonator is presented.
Abstract: A highly sensitive refractive index sensor based on an integrated hybrid plasmonic waveguide (HPWG) and a Metal–Insulator–Metal (M–I–M) micro-ring resonator is presented. In our design, there are t...
70 citations
TL;DR: Several trace gases such as H2O, CO, CO2, NO, N 2O, NO2 and CH4 strongly absorb in the mid-IR spectral region due to their fundamental rotational and vibrational transitions as mentioned in this paper.
Abstract: Several trace gases such as H2O, CO, CO2, NO, N2O, NO2 and CH4 strongly absorb in the mid-IR spectral region due to their fundamental rotational and vibrational transitions. In this work, we propos...
57 citations
TL;DR: In this paper, the authors obtained bright optical soliton solutions from resonant nonlinear Schrodinger's equation by the aid of semi-inverse variational principle for two forms of nonlinear media.
Abstract: This paper obtains bright optical soliton solutions from resonant nonlinear Schrodinger’s equation by the aid of semi-inverse variational principle. The two forms of nonlinear media studied are par...
53 citations
TL;DR: In this article, the authors describe the construction and characteristics of a cryogenic buffer gas source of CaF molecules with a typical duration of 240μs, a mean speed of about 150m/s, and a flux of 5×1010 molecules per steradian per pulse in a single rotational state.
Abstract: Experiments with cold molecules usually begin with a molecular source. We describe the construction and characteristics of a cryogenic buffer gas source of CaF molecules. The source emits pulses with a typical duration of 240 μs, a mean speed of about 150 m/s, and a flux of 5×1010 molecules per steradian per pulse in a single rotational state.
52 citations
TL;DR: One specific class of non-linear evolution equations, known as the Tzitzeica-type equations, has received great attention from a group of researchers involved in nonlinear science as discussed by the authors.
Abstract: One specific class of non-linear evolution equations, known as the Tzitzeica-type equations, has received great attention from a group of researchers involved in non-linear science. In this...
41 citations
TL;DR: In this paper, a 3 to 8 optical decoder was proposed using nonlinear photonic crystal ring resonators, where X, Y and Z serve as input ports and by combination of these ports, one can control which output port to be ON.
Abstract: In this paper, a 3 to 8 optical decoder was proposed using nonlinear photonic crystal ring resonators. For realizing the 3 to 8 decoder, we combined seven 1 to 2 optical decoders. In the proposed structure, X, Y and Z serve as input ports. By combination of these ports, one can control which output port to be ON. The maximum time delay of the proposed structure is about 6 ps.
40 citations
TL;DR: In this paper, the authors present an experimental study of seeded four-wave mixing (4WM) using a diamond excitation scheme (with states from the 5S1/2,5P1/ 2, 5P3/2 and 5D 3/2 terms) in a thermal vapour of 87Rb atoms, and investigate the 4WM spectra under the application of a strong magnetic field.
Abstract: We present an experimental study of seeded four-wave mixing (4WM) using a diamond excitation scheme (with states from the 5S1/2,5P1/2,5P3/2 and 5D3/2 terms) in a thermal vapour of 87Rb atoms. We investigate the 4WM spectra under the application of a strong magnetic field (0.6 T). The Zeeman interaction is strong enough to realize the hyperfine Paschen–Back regime, which has the effect of separating the optical transitions by more than the Doppler width, thereby significantly simplifying the spectral features. We show that this facilitates a quantitative comparison, even in the regime of strong dressing, between experimental data and a simple theoretical model based only on four-level optical Bloch equations.
40 citations
TL;DR: In this article, an analytical study of the propagation of solitons through optical fibres is presented, where a nonlinear Schrodinger equation with spatio-temporal dispersion and quadratic-cubic nonlinearity is considered.
Abstract: This article presents an analytical study of the propagation of solitons through optical fibres. We consider a nonlinear Schrodinger equation with spatio-temporal dispersion and quadratic–cubic nonlinearity. Jacobi elliptic functions are used as an ansatz to extract optical dark and bright solitons as well as Jacobi elliptic solutions. The extended direct algebraic method gives dark and dark-singular soliton solutions. The constraint conditions which guarantee the existence of soliton solutions are listed.
37 citations
TL;DR: In this article, the authors present an experiment to sympathetically cool single protons and antiprotons in a Penning trap by resonantly coupling the particles to laser cooled beryllium ions using a common endcap technique.
Abstract: We present an experiment to sympathetically cool single protons and antiprotons in a Penning trap by resonantly coupling the particles to laser cooled beryllium ions using a common endcap technique. Our analysis shows that preparation of (anti)protons at mK temperatures on timescales of tens of seconds is feasible. Successful implementation of the technique will have immediate and significant impact on high-precision comparisons of the fundamental properties of protons and antiprotons. This in turn will provide stringent tests of the fundamental symmetries of the Standard Model.
TL;DR: In this article, the authors describe an experimental system in which a single ground-state cooled ion is trapped in a linear Paul trap with a cloud of ultracold atoms such that both constituents are in the μK regime.
Abstract: Experimental realizations of charged ions and neutral atoms in overlapping traps are gaining increasing interest due to their wide research application ranging from chemistry at the quantum level to quantum simulations of solid state systems. In this paper, we describe our experimental system in which we overlap a single ground-state cooled ion trapped in a linear Paul trap with a cloud of ultracold atoms such that both constituents are in the μK regime. Excess micromotion (EMM) currently limits atom–ion interaction energy to the mK energy scale and above. We demonstrate spectroscopy methods and compensation techniques which characterize and reduce the ion’s parasitic EMM energy to the μK regime even for ion crystals of several ions. We further give a substantial review on the non-equilibrium dynamics which governs atom–ion systems. The non-equilibrium dynamics is manifested by a power law distribution of the ion’s energy. We also give an overview on the coherent and non-coherent thermometry tools which c...
TL;DR: In this article, all-optical logic operation in quantum-dot semiconductor optical amplifier (QD-SOA) based Mach-Zehnder interferometer considering the effects of two-photon absorption (TPA) occu...
Abstract: We investigate all-optical logic operation in quantum-dot semiconductor optical amplifier (QD-SOA) based Mach–Zehnder interferometer considering the effects of two-photon absorption (TPA). TPA occu...
TL;DR: In this article, classical and quantum limits to the statistical resolution of two incoherent optical point sources from the perspective of minimax parameter estimation were proposed based on the worst-case error criterion and a Bayesian version of the Cramer-Rao bound.
Abstract: I propose classical and quantum limits to the statistical resolution of two incoherent optical point sources from the perspective of minimax parameter estimation. Unlike earlier results based on the Cramer-Rao bound (CRB), the limits proposed here, based on the worst-case error criterion and a Bayesian version of the CRB, are valid for any biased or unbiased estimator and obey photon-number scalings that are consistent with the behaviours of actual estimators. These results prove that, from the minimax perspective, the spatial-mode demultiplexing measurement scheme recently proposed by Tsang, Nair, and Lu [Phys. Rev. X 2016, 6 031033.] remains superior to direct imaging for sufficiently high photon numbers.
TL;DR: In this article, the propagation properties of cosh-Airy beams were theoretically investigated, which can be considered as a superposition of two Airy beams with different decay factors.
Abstract: We theoretically investigate the propagation properties of cosh-Airy beams, which can be considered as a superposition of two Airy beams with different decay factors. We find that the field distribution of cosh-Airy beams is the same as that of Airy beams. Moreover, we find that the evolution of cosh-Airy beams is determined by the parameters of the cosh modulation function, in addition to the transverse scale factor and decay factor of the Airy beams. Our results demonstrate a possible method of manipulating Airy beams in free space. They can also be extended to the study of the propagation properties of cosine-Airy beams (or sine-Airy beams).
TL;DR: In this paper, a specific type of non-linear Schrodinger's equations (NLSEs) is described in the context of nonlinear optics problems, where a wide range of problems in different fields of the applied sciences especially nonlinear optical applications are described by NLSEs.
Abstract: A wide range of problems in different fields of the applied sciences especially non-linear optics is described by non-linear Schrodinger’s equations (NLSEs). In the present paper, a specific type ...
TL;DR: For the past 15 years, tremendous progress within the fields of laser stabilization, optical frequency combs and atom cooling and trapping have allowed the realization of optical atomic clocks with....
Abstract: For the past 15 years, tremendous progress within the fields of laser stabilization, optical frequency combs and atom cooling and trapping have allowed the realization of optical atomic clocks with...
TL;DR: A set of numerical simulation results support the feasibility and security of the proposed scheme and its sensitivity to encryption parameters and its security against occlusion and noise attacks under a number of iterations.
Abstract: This paper proposes a method of double image encryption based on hybrid structured phase mask (HSPM) in the gyrator transform (GT) domain. The scheme becomes more secure by parameters used in the H...
Texas A&M University1, Technical University of Ostrava2, Czech Technical University in Prague3, University of Ottawa4, University of Rochester5, University of Glasgow6, Delft University of Technology7, Cornell University8, University of Strathclyde9, University of Ulm10, University of North Texas11, University of California, Berkeley12, Baylor University13, Harvard University14, Massachusetts Institute of Technology15, California Institute of Technology16, University of Southern California17, University of Southampton18
TL;DR: Many of the world’s leading experts address the following fundamental questions: what is the future of gravitational wave astronomy, and what new technologies and fundamental discoveries might quantum optics achieve by the end of this century.
Abstract: The Winter Colloquium on the Physics of Quantum Electronics (PQE) has been a seminal force in quantum optics and related areas since 1971. It is rather mind-boggling to recognize how the concepts presented at these conferences have transformed scientific understanding and human society. In January 2017, the participants of PQE were asked to consider the equally important prospects for the future, and to formulate a set of questions representing some of the greatest aspirations in this broad field. The result is this multi-authored paper, in which many of the world’s leading experts address the following fundamental questions: (1) What is the future of gravitational wave astronomy? (2) Are there new quantum phases of matter away from equilibrium that can be found and exploited–such as the time crystal? (3) Quantum theory in uncharted territory: What can we learn? (4) What are the ultimate limits for laser photon energies? (5) What are the ultimate limits to temporal, spatial and optical resolution? (6) What novel roles will atoms play in technology? (7) What applications lie ahead for nitrogen-vacancy centres in diamond? (8) What is the future of quantum coherence, squeezing and entanglement for enhanced super-resolution and sensing? (9) How can we solve (some of) humanity’s biggest problems through new quantum technologies? (10) What new understanding of materials and biological molecules will result from their dynamical characterization with free-electron lasers? (11) What new technologies and fundamental discoveries might quantum optics achieve by the end of this century? (12) What novel topological structures can be created and employed in quantum optics?.
TL;DR: For an optical spherical wave propagating in an oceanic turbulent medium, the effect of anisotropy on the received intensity fluctuations was investigated in this paper, for different anisotropic factors.
Abstract: For an optical spherical wave propagating in an oceanic turbulent medium, the effect of anisotropy on the received intensity fluctuations is investigated. For different anisotropy factors, ...
TL;DR: In this article, a triple-wavelength passively Q-switched ytterbium-doped fiber laser using a saturable absorber (SA) based on zinc oxide nanoparticles (ZnO NPs) film is reported.
Abstract: We report on the generation of a triple-wavelength passively Q-switched ytterbium-doped fibre laser using a saturable absorber (SA) based on zinc oxide nanoparticles (ZnO NPs) film. The SA was fabricated by embedding ZnO NPs powder into a polyvinyl alcohol as a host polymer. By properly adjusting the pump power and the polarization state, single-, dual- and triple-wavelength Q-switching are stably generated without additional components (such as optical filter, or fibre grating). For the triple wavelength operation, the fibre laser generates a maximum pulse repetition of 87.9 kHz with the shortest pulse duration of 2.7 μs. To the best of authors’ knowledge, it’s the first demonstration of triple-wavelength passively Q-switching fibre laser using ZnO NPs as a SA. Our results suggest that ZnO is a promising SA for multi-wavelength laser operation.
TL;DR: In this article, a kind of compact fiber-optic sensor based on no-core fiber cascaded with a strong coupling long-period fiber grating (LPFG) is proposed and experimentally demonstrated.
Abstract: A kind of compact fibre-optic sensor based on no-core fibre (NCF) cascaded with a strong coupling long-period fibre grating (LPFG) is proposed and experimentally demonstrated. The sensing mechanism...
TL;DR: In this paper, a measurement of the absolute frequency of the 2S1/2→2F7/2 electric octupole transition in 171Yb+ is presented.
Abstract: The highly forbidden 2S1/2→2F7/2 electric octupole transition in 171Yb+ is a potential candidate for a redefinition of the SI second. We present a measurement of the absolute frequency of this opti...
TL;DR: A new quick response (QR) code-based non-linear technique for image encryption using Shearlet transform (ST) and spiral phase transform and an optoelectronic set-up for encryption is proposed.
Abstract: In this paper, we propose a new quick response (QR) code-based non-linear technique for image encryption using Shearlet transform (ST) and spiral phase transform. The input image is first c...
TL;DR: The traditional measurement method for the horizontal displacement of deep soil usually uses an inclinometer for piecewise measurement and then generates an artificial reading, which takes a long t....
Abstract: The traditional measurement method for the horizontal displacement of deep soil usually uses an inclinometer for piecewise measurement and then generates an artificial reading, which takes a long t...
TL;DR: In this paper, a new type of high-sensitive transmission gas sensor based on the coupled gratings and the corresponding Fabry-Perot-like (FP-like) model for evaluating the resonance peaks are presented.
Abstract: A new type of high-sensitive transmission gas sensor based on the coupled gratings (CGs) and the corresponding Fabry–Perot-like (FP-like) model for evaluating the resonance peaks are presented. The estimated locations of the FP-like resonance obtained by this theoretical model are well agreed with those of the exact results. It is shown that a narrow FP-like channel with high transmissivity occurs in the opaque background of the CGs, and its location is shifted linearly with the variation of the refractive index (RI) of the gaseous analyte. The transmission peak of the sideband can be selected as a reference, and it remains nearly fixed as the RI of the analyte is varied. Good sensing properties of the CGs sensor can be maintained, regardless of whether the two grating membranes are laterally aligned or not. The sensitivity of the CGs sensor is immune to the variation of the RI of the substrate. By selecting the higher order FP-like mode (m = 4), sensitivity as high as 748 nm/RIU with the figure o...
TL;DR: In this paper, a scalar coupled-dipole model in the low excitation limit and an exclusion volume to avoid density-related effects is proposed to support cooperative scattering in cold atoms.
Abstract: Cooperative scattering in cold atoms has gained renewed interest, in particular in the context of single-photon superradiance, with the recent experimental observation of super-and subradiance in dilute atomic clouds. Numerical simulations to support experimental signatures of cooperative scattering are often limited by the number of dipoles which can be treated, well below the number of atoms in the experiments. In this paper, we provide systematic numerical studies aimed at matching the regime of dilute atomic clouds. We use a scalar coupled-dipole model in the low excitation limit and an exclusion volume to avoid density-related effects. Scaling laws for super-and subradiance are obtained and the limits of numerical studies are pointed out. We also illustrate the cooperative nature of light scattering by considering an incident laser field, where half of the beam has a π phase shift. The enhanced subradiance obtained under such condition provides an additional signature of the role of coherence in the detected signal.
TL;DR: In this article, the authors proposed a broadband continuous-wave wavelength converter based on degenerate four-wave mixing in a hydrogenated amorphous silicon (a-Si:H) waveguide with silicon nitride inter-cladding layer.
Abstract: Broadband wavelength conversion based on degenerate four-wave mixing is theoretically investigated in a hydrogenated amorphous silicon (a-Si:H) waveguide with silicon nitride inter-cladding layer (a-Si:HN). We have found that enhancement of the non-linear effect of a-Si:H waveguide nitride intermediate layer facilitates broadband wavelength conversion. Conversion bandwidth of 490 nm and conversion efficiency of 11.4 dB were achieved in a numerical simulation of a 4 mm-long a-Si:HN waveguide under 1.55 μm continuous wave pumping. This broadband continuous-wave wavelength converter has potential applications in photonic networks, a type of readily manufactured low-cost highly integrated optical circuits.
TL;DR: In this article, the authors discuss the major experimental challenges that are to be faced in order to extract meaningful and quantitative information from this class of experiments using existing and near-term laser facilities.
Abstract: The recent development of ultra-high intensity laser facilities is finally opening up the possibility of studying high-field quantum electrodynamics in the laboratory. Arguably, one of the central phenomena in this area is that of quantum radiation reaction experienced by an ultra-relativistic electron beam as it propagates through the tight focus of a laser beam. In this paper, we discuss the major experimental challenges that are to be faced in order to extract meaningful and quantitative information from this class of experiments using existing and near-term laser facilities.
TL;DR: The technique can facilitate holographic reconstruction of individual cells of interest from a large field-of-view digital holographic microscopy data and the complementary phase information in addition to the usual absorption information already available in the form of bright field microscopy can make the methodology attractive to the biomedical user community.
Abstract: We describe a numerical processing technique that allows single-shot region-of-interest (ROI) reconstruction in image plane digital holographic microscopy with full pixel resolution. The ROI reconstruction is modelled as an optimization problem where the cost function to be minimized consists of an L2-norm squared data fitting term and a modified Huber penalty term that are minimized alternately in an adaptive fashion. The technique can provide full pixel resolution complex-valued images of the selected ROI which is not possible to achieve with the commonly used Fourier transform method. The technique can facilitate holographic reconstruction of individual cells of interest from a large field-of-view digital holographic microscopy data. The complementary phase information in addition to the usual absorption information already available in the form of bright field microscopy can make the methodology attractive to the biomedical user community.