For the first time, stimulated Raman scattering was detected in a microcrystalline powder of lead nitrate under excitation by ultrashort (60 ps) pulses of a YAG:Nd 3+ laser operated at a wavelength of 532 nm. The stimulated Raman scattering of light on the lattice librational and full-symmetric (NO 3 )-ion modes was observed. The performed studies open the possibility for creating lasers based on stimulated

In this paper we present the measurements and comparison of surface plasmon wave (SPP) propagation length at the practically important telecom wavelength (1560 nm) as well as in the near infrared and visible spectral ranges. The measurements were carried out for plane SPP waves excited on Ag film surface using optical microscopy of SPP waves in the far field. We also demonstrate the possibility of

The absorption of high-power nanosecond laser pulses in a porous matter is investigated through theoretical and numerical calculations. The effects of structural properties of the porous target such as size of pores and thickness of solid elements on the laser absorption are investigated. The time and space-dependent absorption coefficient of the laser created partially homogenized plasma is used in

Quantum computing is a new mode that follows the laws of quantum mechanics. It performs computational tasks based on the control of quantum units. From the view of computable problems, quantum computers can only solve the problems that traditional computers can solve, but considering the efficiency of computation, due to the existence of quantum superposition, some known quantum algorithms are exponentially

We report on the first demonstration of a diode-pumped passively mode-locked Tm,Ho:LiYF 4 laser. Stable continuous-wave mode-locking is achieved by employing a single-layer graphene as a saturable absorber (SA). For a reflection-type graphene-SA, the laser delivers 5.2 ps pulses at ~2051 nm with an average output power of 40 mW at a repetition rate of 89.86 MHz. With a transmission-type graphene-SA

We investigated the effect of focusing sub-nanosecond laser radiation with varied fluence onto the surface of different flat and nanostructured targets utilized in ultra-high intensity laser-plasma experiments. Thus, we modeled the action of the prepulse, referred to as an amplified spontaneous emission pedestal, typically present for a relativistic (with peak intensity over 10 18 W cm −2 ) laser pulse

The actual theoretical research investigates the resonant spontaneous bremsstrahlung (RSB) of ultrarelativistic electrons under the condition of scattering on a nucleus in the field of a weak electromagnetic wave. The progression of the functional mechanism indicates the transformation of the intermediate virtual electron into the real particle state. Therefore, the initial second order process with

The conversion of infrared radiation of a Tm 3+ :YAP laser at a wavelength of 1.93 µm into visible light in [(ZrF 4 ) 0.4 –(BiF 3 ) 0.6 ] 100− x –(HоF 3 ) x ( x = 1.5 or 5 wt%) ceramic samples was investigated. The emission bands at wavelengths of 650 nm, 900 nm and 1100 nm corresponding to transitions from ##IMG## [http://ej.iop.org/images/1612-202X/17/4/045701/lplab7346ieqn001.gif] , ##IMG## [http://ej

A compact continuously tunable dual-wavelength source of radiation based on a diode pumped Nd:AG laser and an intracavity degenerate optical parametric oscillator (IDOPO) was demonstrated for the first time. The generation of two pulses of radiation with mutually orthogonal polarization and a wavelength difference from 0 to 500 nm is realized. The pulse energy reached ~1 mJ with a pulse duration of

Density matrices of pure multiphoton Fock polarization states and their resultant reduced density matrices of mixed states are expressed in similar ways in terms of matrices of correlators, defined as averaged products of equal numbers of creation and annihilation operators. The degree of entanglement of considered states is evaluated for various combinations of parameters of states and characters

A two-level atom interacting with a single-mode cavity is considered. The atom-cavity system is driven by a classical field with the homodyne-mediated feedback. The influences of the driving field and two types of the feedback on the precision of the phase estimation are investigated. The results show the quantum Fisher information (QFI) can be preserved by the homodyne-mediated feedback and the classical

We report a compact, low cost, multi-color diode laser based illumination system for display and laser-projectors. An innovative speckle reduction system based on spatially structured and temporally varying beams was designed and developed. Three primary color lasers were efficiently combined and then made incident onto electromechanically controlled diffractive optical elements. This system splits

In this study, a facial and effective method is proposed to improve interfacial bonding strength via a hierarchical microscale taper array fabricated by a femtosecond laser. Copper interfaces with microstructures can be easily sintered by nano-silver paste under low bonding temperature and additional pressure. In order to analyze the sintering quality, the interconnected cross-section is characterized

In this paper, we study the transformations that are obtained in one-way quantum computation on continuous-variable cluster states of various configurations. Of all possible cluster configurations, we choose those that are suitable for universal Gaussian operations.

The processes occurring during photobleaching of a new nonlinear optical co-crystal 2,6-diaminopyridine-4-nitrophenol-4 nitrophenolate are investigated. Using infrared spectroscopy of co-crystals, destruction of an aminopyridine-nitrophenol molecular complex by photoactinic radiation without breakage of aminopyridine and nitrophenol molecules integrity is shown. Differential scanning calorimetry and

The state of mode coupling in bent and twisted step-index plastic-clad silica fibers is investigated in this article by the numerical solving of the time-independent power flow equation. The coupling length L c at which the equilibrium mode distribution is achieved and the length z s of the fiber required for achieving the steady-state mode distribution are obtained. It was found that the bent and

Loose bunches of soliton molecules (SMs) in a passive mode-locked fiber laser with a WTe 2 saturable absorber are observed using the photonic time-stretching (TS) technique. Due to the large temporal separations between the SMs, the TS profiles of the loose bunches appear as the intensity superposition of the spectral interference fringes of the adjacent SMs. The bandwidth limitations and the electronic

In this paper, spectroscopy and laser results obtained with new active medium Yb,Ho:GGAG (gadolinium–gallium–aluminum–garnet) emitting laser radiation at 2.09 ##IMG## [http://ej.iop.org/images/1612-202X/17/3/035801/lplab6d61ieqn001.gif] m and 2.94 ##IMG## [http://ej.iop.org/images/1612-202X/17/3/035801/lplab6d61ieqn002.gif] m are shown. The absorption, emission cross-section, and radiative decay time

Quantum coherence underlies different forms of quantum correlations. We investigate the nonlocal advantage of quantum coherence (NAQC) for the thermal equilibrium states of both the spin-1/2 and the spin-1 Heisenberg XXZ models. By considering the NAQC formulated within two slightly different frameworks, we showed that their values can always be enhanced by tuning strength ##IMG## [http://ej.iop.o

Using an Er-doped fiber laser as a test bed, here we for the first time experimentally demonstrate the simultaneous effect of the fast scale (round-trip time) and slow scale (thousands round-trip time) instabilities on the emergence of breathers similar to the Akhmediev breathers, Peregrine solitons, and partially mode-locked chaotic solitons. The anomalous statistics of the laser output power justifies

In this work we present an algorithm of building an adequate model of polarizing quantum state measurement. This model takes into account chromatic aberration of the basis change transformation caused by the parasitic dispersion of the wave plates crystal and finite radiation spectral bandwidth. We show that the chromatic aberration reduces the amount of information in the measurements results. Using

In this paper, we propose an asymmetric interference based encryption (IBE) using a modified error-reduction phase retrieval algorithm (mERPRA) in a structure of optical interference. Unlike previously proposed IBE schemes, the ciphertext in our scheme has less pixels than the original image. What is more important, a plaintext-dependent private key can be retrieved by using mERPRA with a fixed amplitude

An analytical method for few-mode erbium doped fiber amplifiers (EDFAs) is proposed by introducing the uniformity coefficient of population inversion. The validity of the derivation process of the analytical method is identified by the numerical method. It is shown that the more uniform the transverse distribution of erbium ion population density at the metastable level, the closer the analytical solution

We propose an alternative non-Markovianity measure of open quantum systems, which is based on max-information. The max-information is a one-shot generalization of the mutual information derived from the max-relative entropy. This operational interpretation provides a new site for viewing the non-Markovian process. As applications, some typical noisy channels have been investigated: for phase damping

We study the Gaussian steering between Unruh modes in the two-mode squeezed states shared by two accelerated observers. We find that the steerability degrades with the increasing of the accelerations of the two observers. An interesting discovery is that the observer who has larger acceleration has stronger steerability than the other one. The condition for the occurrence of maximal steering asymmetry

We have experimentally observed ultrashort pulse in a simple, all-polarization-maintaining fiber, master oscillator and power amplifier laser. A semiconductor saturable mirror (SESAM) module is used as the mode locker. The ultrashort pulse exhibits perfect Gaussian spectrum without any fine structure. The 20 dB pulse spectral width is 28 nm, and the pulse duration directly output from the oscillator

The method for visualization of the low-scattering objects inside the bulk of the high-scattering tissue is presented. The method can contrast the low-scattering object of interest not only from the high scattering surroundings but from the noise region below the tissue image as well. The proposed method was applied for the visualization of the rodent and human cochlea volume.

We present a generalized criterion for maximally entangled nine-qubit states, whose minimum averaged subsystem purity should be equal to 1/14. In this note, we prove that the absolutely maximally entangled state for nine qubits does not exist. In other words, we pronounce that the pure (9, 1, 5) 2 quantum error-correcting code does not exist. Further, we construct a new genuine nine-qubit maximally

Here, we report our studies on the continuous loading of a U-magneto-optical trap (U-MOT) on an atom-chip with a rubidium-(Rb)-vapor-generated background using a dispenser source in an ultra high vacuum environment. Using the U-MOT loading curves, the partial pressure due to the Rb vapor and the pressure due to the background gas have been estimated near the MOT cloud position. The estimated pressure

Organic microresonators are highly attractive for numerous applications including biosensing, optical switching and metrology. Adding chiral materials to resonators can enhance their sensing properties due to the appearance of chiroptical effects. Here we study experimentally resonant multiphoton processes in spherical microresonators with the diameter of 2–12 ##IMG## [http://ej.iop.org/images/161

Plasma-based waveguides are currently employed for laser wakefield acceleration to extend the focal region of laser beams. A parabolic transverse plasma density profile, suitable for laser guiding, can be established in a dielectric capillary as a consequence of a discharge in gas. In this work, we report on a new ray tracing model, based on the Zemax software, able to simulate the envelope of a laser

The one-qubit teleportation protocol is one of the most well-known topics of quantum information theory. Indeed, the goal of this quantum protocol is to teleport an arbitrary quantum state. Herein, we investigate the entropic uncertainty relation in the presence of quantum memory (EUR-QM), quantum discord (QD), and fidelity of teleportation under dephasing, dissipative, and noisy environments. We relate

We propose a scheme for implementing robust SWAP gate on two distant atoms that are confined in two spatially separated single-mode optical cavities connected by an optical fiber. The SWAP gate cannot be attained by using adiabatic passage for such a physical model, but we achieve it by following transitionless quantum driving, a method of shortcuts to adiabatic passage. In addition, during the execution

A new generation lidar (LIght Detection And Ranging) based on a diode laser with eye-safe energy density (~10 nJ cm −2 ) and a single photon avalanche photodiode was used for the first time, to our knowledge, to detect clouds along the Garabashi glacier near the Elbrus mountain summit. We have observed single- and multilayered clouds near the Elbrus volcano summit from the Garbashi camp located at

Quantitation of hepatitis B virus deoxyribonucleic acid (HBV DNA) is the most accurate method for determining the infection level of hepatitis B. It is a very meaningful means of detecting the different replication states of HBV infection. In this study, HBV DNA was detected and quantified in 499 patients with hepatitis B by confocal Raman spectroscopy combined with multivariate analysis. The effective

Quantum secret sharing is an important branch of quantum cryptography. In this paper, we firstly propose a simple four-party quantum secret sharing scheme with entangled states. Since the noisy channel has a great influence on the shared quantum secret, we analyze the impact of the noisy channel on quantum secret sharing and obtain the expression among the fidelity, noisy coefficient and shared quantum

We propose a method for the automated in vivo thickness measurement of the human eardrum in OCT imaging. The method is based on extraction curvilinear structures using eigenvectors and eigenvalues of smoothing image Hessian (Steger method). This allows for extracting the central line of the eardrum and calculating the normal to each point. The latter circumstance makes it possible to find the proper

We revisit a recently proposed scheme (Ciappina et al 2019 Phys. Rev . A 99 043405) for accurate measurement of electromagnetic radiation intensities in a focus of high-power laser beams. The method is based on the observation of multiple sequential tunneling ionization of atoms and suggests determination of the peak intensity value from the appearance in the focal area ions with a certain charge number

We report an experimental implementation of dynamical holographic tweezers for single trapped atoms. The tweezers are realized with dynamical phase holograms displayed on the liquid crystal spatial light modulator. We experimentally demonstrate the possibility to trap and move single rubidium atoms with such dynamic potentials, and study its limitations. Our results suggest that high probability transfer

We report an ultra-low repetition rate self-started mode-locked fiber laser at 1.55 µ m spectral region with a sub-20 ps pulse duration at repetition rate of less than 100 kHz leading to high energy and peak power pulses. A repetition rate of 13.8 kHz with the pulsewidth of 17 ps is then achieved and the issue of multiple pulses is mitigated in the linear cavity structure by proper selection of semiconductor

Multistaircase spiral phase plates (MSSPPs), which are alternatives to ideal continuous surface SPPs, are commonly applied to passively generate optical vortices (OVs). In addition, one of the universal applications of OVs is in orbital angular momentum (OAM)-multiplexed quadrature amplitude modulation (QAM) optical communication systems. In this paper, the relationship between bit error rate (BER)

We experimentally demonstrate the generation of a temporal pulse doublet from the propagation of an initial super-Gaussian waveform in a nonlinear focusing medium. The picosecond structures are characterized both in amplitude and phase and their close-to-Gaussian Fourier-transform limited shape is found in excellent agreement with numerical simulations. This nonlinear fiber-based single-stage reshaping

In this paper new method of asymmetric optical encryption is presented. It is based on the double encryption using spatially incoherent illumination: to obtain a ciphertext a plaintext is encoded twice, first time by sender, second time—by recipient. This way no exchange of encryption keys is required. Two variants of this method were analyzed: one in which both encryption procedures are implemented

The formation of stable single solitons and various bound states based on a graded index multimode fiber (GIMF) is investigated experimentally for the first time. Taking advantage of the principle of nonlinear multimode interference, a 143.5 cm length of GIMF is bent and two polarization controllers are used to achieve stable passive mode-locking. The spectrum of single solitons centers on 1590.5 nm

The improvement potential of ultrafast all-optical switching by soliton self-trapping, using all-solid dual-core fibres with high index contrast, was analyzed numerically. The study of the femtosecond nonlinear propagation was performed based on coupled generalised nonlinear Schrödinger equations considering three fibre architectures: homogeneous cladding all-solid, photonic crystal air-glass, and

The guiding of a 6 GHz electromagnetic (EM) wave along a plasma filament produced by intense femtosecond laser pulses is investigated with the electromagnetic simulation software XFDTD. The results confirm that the plasma filament can guide the EM wave over a long distance, with low attenuation relative to freely propagating the signal. Furthermore, the filament can change the phase wavelength of the

The spectroscopic and laser properties of mixed fluoride Tm:CaF 2 –SrF 2 crystals were investigated. The 1.9 ##IMG## [http://ej.iop.org/images/1612-202X/17/2/025802/lplab5f58ieqn001.gif] m radiation was obtained in two samples with Tm 3+ ion doping concentrations of 1.0 mol% and 2.0 mol% under laser diode pumping at 763 nm. The highest slope efficiency of 32.5% and the widest laser tuning range of

A stable single longitudinal mode optofluidic microcavity laser based on an antiresonant hollow-core fiber (AR-HCF) is proposed and experimentally demonstrated. A hexagonal silica ring inside the AR-HCF is used as the resonator of the optofluidic laser. Experimental results show that the laser can operate in a stable single longitudinal mode without optical mode-selection device and only by introducing

The master equation for the atom-field system with degenerate atomic levels and two polarization modes of the quantized field in a damped micro-cavity is obtained in the basis of eigenvectors of the interaction operator. The solution for the lossless cavity is obtained. The analytic expressions for the probability of emission of the photon in the cavity by an excited atom and of the photon polarization

We demonstrate a tunable solid-state polymer dye laser with quasi-longitudinal pumping by two green ( λ = 513 nm) laser diodes. Tuning curves with a maximum efficiency of 13% were attained, using a plate of crystalline quartz (Lyot filter) for wavelength selection. In a three-mirror cavity with partial compensation of astigmatism, the total tuning range was 62 nm (from 545 nm to 607 nm) for pyrromethene

A combined mechano- and chemo-bactericidal nanomorphology, consisting of periodical surface structures on silicon with deposited nanoparticles of selenium, tellurium oxide, antimony oxide and silver, was fabricated via laser ablation in deionized water with femto- and nanosecond laser systems. The resulting functional surfaces were tested against the formation of Staphylococcus aureus biofilms, and

We theoretically demonstrate the Fano resonance and the conversion from fast to slow light in a hybrid semiconductor quantum dot (SQDs)-metal nanoparticle (MNPs) with cavity quantum electrodynamics treatment. The absorption spectra of the weak probe field exhibit a series of asymmetric Fano line shapes and their related optical propagation properties, such as fast and slow light effects, are investigated

Based on the nonincreasing property of quantum coherence via skew information under incoherent completely positive and trace-preserving maps, we propose a non-Markovianity measure for open quantum processes. As applications, by applying the proposed measure to some typical noisy channels, we find that it is equivalent to the three previous measures of non-Markovianity for phase damping and amplitude

The optical properties and morphology of laser generated aluminum and copper phthalocyanine nanoparticles (nAlPc and nCuPc) in water are experimentally studied. A near-infrared laser source of nanosecond pulse duration was used for the fragmentation of a Pc micro-powder suspended in H 2 O. The extinction spectra in the visible and near-IR range of nanoparticle colloidal solutions in milli-Q water were

We report on the demonstration of a symmetrically cooled thin-disk laser concept using Ti:sapphire for the gain medium and plano-convex shaped single crystal diamond as intracavity heat spreaders. This allowed us to increase the absorbed pump intensity by at least a factor of five compared to a previously reported Ti:sapphire thin-disk oscillator.

In this study, laser-induced breakdown spectroscopy (LIBS) was applied to detect some samples of tea, which were picked in three different seasons: spring, summer, and autumn. The relationship between some elements in the tea and the characteristics of its origin was analyzed. By comparing the relative intensity of the characteristic spectral lines of some elements in the tea samples harvested in different

We have investigated nonlinear laser ̶ matter interaction inside silicon under tight focusing conditions by continuously tuning driving pulse duration from femtosecond to picosecond timescales. Such tailoring of laser pulse width provides a new route for energy delivery into a microvolume avoiding two-photon absorption and plasma defocusing in the pre-focal region. As a result, we have achieved values

In this paper, we demonstrate that the intensity difference squeezing (IDS) of parametric amplified four-wave mixing (PA-FWM) can be modulated by the phase-sensitive dressed effect in a hot rubidium (Rb) atomic system. The introduction of phase-sensitive dressed effect can enhance the degree of IDS of PA-FWM to −8.1 dB, as compared to that in the phase-insensitive dressed PA-FWM of −6.6 dB. The phase-sensitive

Quantum fluctuations of soliton pulses produced via two-soliton fission in the optical dispersion oscillating fiber were investigated using perturbation analysis and back-propagation method. It was shown that in the fiber with periodic dispersion, two-soliton pulses decay to two similar entangled pulses having the same photon numbers of modes and different phases due to shifts of carrier frequencies

Early security proofs of the keys in quantum cryptography systems were based on the assumption that the transmitting and receiving stations were completely isolated from the outside world—the eavesdropper. However, this condition cannot be implemented in practice, since quantum cryptography systems are open systems, in the sense that an eavesdropper can have indirect access, for example, through a