A scheme is addressed to generate the macroscopic entanglement and the output squeezing of optomechanical system with a single four-level atom. Applying the logarithmic negativity to measure entanglement, we analyze the effect of the coupling strength between the cavity and the atom on the entanglement of the cavity and the movable mirror. It is found that the robustness of the entanglement is enhanced

The results of investigation of light filament self-reconstruction after penetration through the air gap in fused silica at anomalous and normal group velocity dispersion are presented. It is revealed that at anomalous dispersion the light bullet formed before the gap was recovered after passing some distance behind the gap up to 1 mm length. This distance increased with the gap length and the bullet

The regulation of multiple filaments during an intense femtosecond laser propagation in a transparent optical medium is still challenging. In this study, by tracing the phase variation of the laser pulse during the propagation, the effect of the beam ellipticity on the generation of multiple filaments was investigated using the efficient π -phase plate. The spatial distribution of the generated multiple

Asymmetric quantum cloning (QC) is important for eavesdropping due to non-cloning quantum theorem. In this paper we propose a method to produce an asymmetric QC using weak measurement. Compared with previous proposals (1999 Phys. Rev. A 60 2764, 2004 Phy.s Rev. A 69 062316), the fidelity of one copy can be improved, while the other one reduces more smoothly. Also, the average fidelity of two copies

In this study, for the first time, we apply optical coherence elastography to map and monitor slow strains caused by residual stresses in cartilaginous tissues subjected to thermomechanical laser-assisted reshaping in regimes used for the preparation of implants in otolaringological surgery. Such laser-fabricated implants made of the patient’s rib cartilage have already been successfully used for treating

A scheme is proposed for the preparation of entangled states in a pair of cavities, including Knill–Lafamme–Milburn (KLM) states and Bell states. Success probabilities for preparation of entangled states are near unity. The numerical simulation result shows that this scheme has high fidelity and is robust against imperfect operation. The obvious advantage is both the KLM states and Bell states can

Coherence distillation and dilution are two core problems in the manipulation of quantum resources. In this paper, we propose deterministic coherent distillation and dilution protocols, which fully demonstrate the change from the pure state to the maximum coherent state and vice versa. Our protocols can reach the theoretical value introduced in the upper bound proposed by Liu et al recently [Liu C

Autonomous directional water flow was demonstrated on a laser-microstructured steel-supported polymethylmetacrylate (PMMA) film with a surface tension gradient. For this purpose, a 4 μ m-thick PMMA layer on AISI 304 steel surface was raster-scanned in air in ablative mode by a 1064 nm, 100 ns laser beam in a number of lines, with the amount and topography of ablated PMMA analyzed by optical microscopy

The conditions are identified, under which a figure-of-eight all-polarisation-maintaining fibre laser with two independently pumped active media, each in one of the two cavity loops, generates soliton molecules with adjustable number of solitons in the molecule. The soliton count in the molecule may be reproducibly set between 2 and 6 by adjustment of the ratio of the pump powers of the active media

We report the results of our theoretical investigation into the impact of the Q-switch rise time on three key parameters of the output pulses in an actively Q-switched fiber laser, namely the multipeak phenomenon, pulse energy, and pulse peak power. Our investigation is conducted over a Q-switch time range of up to 12 times the cavity round-trip time (τ round ). We show that when a longer Q-switch

We report on the estimation of blood content and vessel volume fraction changes in the microcirculatory bed of human skin under controlled mechanical compression using 3-dimensional optoacoustic (OA) angiography. A consecutive decrease in the fraction of blood vessels and skin blood content as a result of an increase in pressure from 0 to 72 mmHg applied to the imaged area was demonstrated by means

Recently coronavirus infection 2019 (COVID-19) was declared as a Public Health Emergency by the World Health Organization. Extensive measures to reduce person-to-person transmission of COVID-19 and scientific research have been developed aiming to combat it. The idealization of vaccines will be of great help, but they will have to be constantly redone due to the high frequency of mutation of the virus

We present a simple scheme for the complete analysis of hyperentangled Bell states in polarization and spatial-mode degrees of freedom (DOFs) assisted by time-bin–frequency hyperentanglement. In previous schemes of distinguishing the 16 hyperentangled Bell states, many non-linear interaction systems are widely used to construct a quantum gate, such as cross-Kerr non-linearity, quantum-dot spin in an

We have synthesized luminescent YVO 4 : Yb, Er nanoparticles (NPs) in the size range of 10–700 nm. A bright green luminescence of the dry NPs powder due to Er 3+ ions emission centered at 526 and 550 nm was compared for upconverting and downconverting laser excitations at 980 nm and 257 nm, respectively. Moreover, the NPs exhibited bright luminescence in colloidal water solution upon 980 nm laser irradiation

The aim of this study was to investigate the application of optical coefficients obtained from cross-polarization optical coherence tomography (CP OCT) data to differentiate breast cancer tissues from normal breast tissues. For this, surgically obtained breast specimens from 35 patients were investigated using CP OCT in order to construct pseudocolor en face OCT maps based on a calculation of three

A lightweight authenticated semi-quantum key distribution (LASQKD) protocol is proposed for secure communication. By pre-sharing a master key and adopting a one-way communication strategy, the proposed protocol allows a quantum user and a classical user to share secret keys without using an authenticated classical channel and any Trojan horse detection device. Security analyses show that the proposed

The nonlinear optical properties of a nematic liquid crystal (NLC 1289) were experimentally studied according to the intensity and polarization of the pump radiation at a wavelength of 1.56 μ m. It is shown that the maximum generation efficiencies of the second and third harmonics correspond to different polarization characteristics of the main radiance. In the investigated range (10 6 … 2 ∙ 10 7 W

The hybrid laser system based on the picosecond fiber ring laser with a two fiber preamplifiers and terminal bulk amplifier was demonstrated. The cavity length of the master oscillator was 200 meters, the mode-locking regime was realized by the effect of nonlinear polarization evolution. After amplification and conversion of radiation to the second harmonic while using the lithium niobate crystal,

For the first time, with the use of I-scan and z-scan techniques, the five-photon absorption cross-section in a CaF 2 sample has been measured to be σ 5 = 5 × 10 −148 cm 10 s 4 at 473 nm. The applicability of the technique and the contribution to the measured absorption of an avalanche and tunnel ionization are discussed.

We present an optical scientist vision for a photonic platform for real-time polymerase chain reaction (qPCR) and reverse-transcription qPCR (qRT-PCR) that integrates a rapid-cycle fiber-optic PCR chamber with feedback-controlled laser heating, online fluorometric detection of PCR products, and all-optical thermometry using an optical readout from color centers of diamond nanoparticles. We show that

An endoscopic optical coherence tomography (OCT) probe that can perform full circumferential scans using a circular array of six micro-electro-mechanical system (MEMS) mirrors has been developed. Inside the OCT probe, each of the six MEMS mirrors forms an independent scanning unit; circumferential OCT images are acquired by off-centre scanning and combining the image data from the individual multiple

The bubble regime of the laser wakefield acceleration is one of the most recent and promising mechanisms for generating quasi-monoenergetic electron beams. In this work, we propose to study the dynamics of bubble (a wake structure devoid of electrons created in underdense plasma by a highly-intense ultrashort laser pulse) in a petawatt regime. The dependence of the electron beam energy and the quality

We study theoretically the spectra of second, third and fourth harmonics from multimode bright squeezed vacuum obtained by type-I broadband high-gain parametric down conversion. The different contributions to the spectra of harmonics are analyzed. A new method for the measurement of second-order correlation function g (2) (0) of parametric down conversion radiation is suggested.

A scheme of plasma–chemical mid-IR hydrogen fluoride (HF) lasing is proposed, in which electrons of femtosecond filament are produced in argon and give rise to a chain of plasma–chemical reactions occurring with SF 6 and H 2 added to the argon bath and resulting in the formation of vibrationally excited HF molecules. The conditions for the occurrence of amplified spontaneous emission and lasing in

In this work, we realize a high-power, narrow linewidth, linearly polarized laser output based on a compact all-fiber polarization maintaining (PM) master oscillator power amplifier. The seed is a fiber oscillator laser (FOL) with few-longitudinal-mode for spectral broadening suppression. The spectral broadening characteristics in the FOL seed and in the PM-amplifier with different pumping schemes

We presented a novel design of a microring resonator based on a subwavelength grating (SWG) double-slot waveguide (WG) due to its enhanced sensitivity. The paper is divided into two parts. In the first part, we studied and compared the modal characteristics of SWG ridge, single-slot and double-slot WGs. A large value of 0.78 for overlap intensity integration in the upper cladding for SWG double-slot

In recent decades, various multipartite entanglement measures have been proposed by many researchers, with different characteristics. Meanwhile, Scott studied various interesting aspects of multipartite entanglement measures and he has defined a class of related multipartite entanglement measures in an obvious manner. Recently, Jafarpour et al (2015 Int. J. Quantum Inform. 13 1550 047) have calculated

For quantum systems with broken parities, a transition can appear for any two different states, and cyclic transition structures can be generated for the lowest three levels. Based on these loop transitions, we discuss how to achieve high-precision localization effects for physical objects with broken parities, i.e . chiral molecules and asymmetric quantum wells. In a Δ-type three-level system interacting

A current trend in modern bioinformatics is representation of nucleotide sequences in the form of gene-based (GB) speckles. In this letter GB-speckles have been processed using the s-LASCA (laser speckle contrast analysis) technique. Statistical properties of s-LASCA images of GB-speckles have been analyzed. It is shown that application of the s-LASCA technique allows us to essentially increase the

Er 3+ /Yb 3+ /Ho 3+ :CaLaGa 3 O 7 (abbreviated as Er/Yb/Ho:CLGO) and Er 3+ /Yb 3+ /Eu 3+ :CaLaGa 3 O 7 (Er/Yb/Eu: CLGO) crystals were grown by Czochralski technology and detailed spectroscopic analyses were carried out. The effects of Ho 3+ and Eu 3+ on the spectroscopic properties and mutual energy transfer mechanisms were investigated. It is found that the introductions of Ho 3+ and Eu 3+ are helpful

We present a passively mode-locked all-fibre ring laser, working in the near-infrared region. The burst of multiple pulses generation is achieved by modifying the transmission output of the saturable absorber. Consequently, multiple modes are stimulated within the laser cavity and multiple wavelengths of operation from 1038 to 1082 nm are accomplished. Furthermore, average power and pulse energy, up

Optical soliton processing techniques are expected to play a major role in future ultrafast optical transmision lines, optical computing, and the synthesis of new powerful soliton lasers. We propose the use of a dispersion oscillation fiber as a new versalite tool to control soliton eigenvalues. Using a fiber with sine-wave variation of the core diameter along the longitudinal direction, we can change

As the oxide-induced disruption from silicon dioxide substrate would greatly decrease the thermal property of graphene, strategies to optimize the thermo-optical response through controlling laser spot size, layer number and covering length of graphene layer are experimentally studied and discussed. An all-optical controlled fiber Mach–Zehnder interferometer with multilayer and monolayer graphene achieved

A near infrared spectrometer based on the self-scanning Tm-doped fiber laser is developed. The spectrometer is applied to measurements of the water nuclear spin isomer abundances using water absorption lines in the vibrational band ##IMG## [http://ej.iop.org/images/1612-202X/17/6/065702/lplab88d5ieqn1.gif] {$\nu_2+\nu_3$} near 1.91 µ m. The ortho/para ratio of water nuclear spin isomers is measured

We propose a scheme to investigate the topological phase transition in the generalized one-dimensional Su–Schrieffer–Heeger (SSH) model based on a circuit quantum electrodynamics (QED) lattice with frequency modulation. We find that, if we keep the resonant counter rotating wave terms to map the p -wave superconducting pairing terms in the topological superconductor by dint of frequency modulation

Ultrathin metasurfaces provide a completely new route to achieve an invisibility cloak through local phase compensation. However, conventional carpet cloaking only works at a single frequency. Here, we propose a dual-wavelength carpet cloaking based on a single layer metasurface. Based on the electromagnetic coupling effect between the outside split square loop and inner metal structure array, the

Pronounced elastic nonlinearity intrinsic to many biological tissues makes the Young’s modulus (stiffness) of the tissue strongly dependent on the current strain and stress. The measured modulus may vary several times for rather moderate tissue straining within a few per cent, such strains being quite typical for compressional optical coherence elastography (C-OCE). This pronounced stiffness variability

We report a detailed experimental demonstration of the Goos–Hänchen (GH) shift of light in total internal reflection condition for a Gaussian mode laser beam of 633 nm passing through an air-glass interface. The quantum weak measurement (QWM) technique has been exploited as a weak value amplification scheme to observe the amplified optical GH shift. The amplification of the GH shift depends on the

We present a thorough characterization of a red-emitting mode-locked semiconductor disk laser producing the first stable fundamental mode-locked pulse train in the red spectral range. The achievable temporal FWHM pulse length of the Lorentzian-shaped pulses is just below 3 ##IMG## [http://ej.iop.org/images/1612-202X/17/6/065001/lplab881fieqn1.gif] {$\,\mathrm{ps}$} which represents the shortest pulses

High speed pulse generation with adjustable output characteristics in the mid-infrared (MIR) wavelength is a challenge due to the lack of high speed optoelectronic modulator operating at this band. In this paper, we proposed a MIR actively mode-locked laser based on cross-band all-optical injection modulation. The proposed laser is modulated by injecting 1.55- μ m pump pulses into the specially-designed

We derive criterion in the form of inequality based on quantum Fisher information and quantum variance to detect multipartite entanglement. It can be regarded as complementary of the well-established positive partial transpose criterion in the sense that it can also detect bound entangled states. The inequality is motivated by Y Akbari-Kourbolagh et al [Phys. Rev A. 99, 012304 (2019)], which introduced

Radiation at a wavelength of 563 nm was achieved using an all-solid-state laser system based on a diode-pumped actively Q-switched Nd 3+ :YVO 4 laser with intra-cavity second harmonic generation in LBO followed by intra-cavity Raman conversion in Ba(NO 3 ) 2 . The output power of 101 mW was achieved under a pump power of 5 W and a modulation frequency of 12.7 kHz with a slope conversion efficiency

We propose a scheme to realize a single-photon diode and circulator using two waveguides chirally coupled to a five-level M -type atom. Two external control fields are introduced to drive the emitter. Non-reciprocal single-photon propagation can be completed in our scheme, which underpins the single-photon diode and circulator. The single-photon diode can work well at special frequency points of the

Over the past decade Raman spectroscopy has been successfully used to study the cell structure of various pathogens, including M. tuberculosis (MbT). It is especially important due to the high ability of pathogen to become resistant to anti-tuberculosis drugs usually leading to a lethal outcome. In the present study we investigate deactivated MbT strains with different drug sensitivity (extra-, multi-

We present a technique for suppression of wavelength competition in rare-earth-doped fiber lasers and for obtaining simultaneous lasing at tens (up to several hundred) of laser lines with wavelength spacing down to 50 pm. An ytterbium-doped fiber laser is used for experimental demonstration. Spectral selection is based on a built-in Lyot filter whose length can be selected to set suitable wavelength

We study the Q-factors of whispering gallery modes on the surface of standard optical fibers using both spectral and ring-down measurements and show that annealing by the fire torch yields Q-factors higher than 10 7 . In this case, however, variations of the effective radius are introduced, that make the mode spectrum complicated as a number of modes with a nonzero axial component of the wave vector

A high-energy chirped pulse amplification system based on a Yb doped fiber seeder, two-stage single crystal fiber (SCF) amplifier with a simple single-pass structure is demonstrated in this work. An amplified power of 52.2 W with a beam quality of less than 1.3 at 200 kHz is obtained, to our best knowledge, this is the highest power obtained with a single-pass amplification structure of the SCF with

In strong oceanic turbulence, the performance of M -ary phase shift keying subcarrier intensity-modulated optical wireless communication (OWC) links is investigated in terms of the bit-error-rate (BER) by considering the effect of anisotropy of the oceanic channel. To calculate the BER of the OWC link, a gamma–gamma statistical channel model is adopted. The extended Huygens–Fresnel principle and the

We report on an Yb-doped all-polarization maintaining fiber mode-locked laser based on nonlinear-amplifying-loop mirror and 3 × 3 coupler. Thanks to this coupler inducing a non-reciprocal phase-bias, the mode-locked regime can be easily achieved at the high repetition rate of 52 MHz. The cavity delivers an average power of 62 mW corresponding to a pulse energy of 1.2 nJ. We have finally demonstrated

We report a compact and robust micro air cavity (MAC) incorporated tip tapered photonic crystal fiber (PCF) based interferometer point probe for refractive index (RI) sensing. Two sections of PCF are spliced and tapered and the tapered collapsed section is cleaved to form a tip tapered PCF. One end of the PCF is spliced with a single mode fiber while the tapered tip of PCF is subjected to laser micromachining

It is known that in the small quantum parameter regime the Breit-Wheeler electron-positron pair creation cross section is extremely sensitive on the photon energy and on the background field. We present the dependence of positron yield on laser intensity in laser-foil interactions with the help of analytical theory and particle-in-cell simulaitons. These particles are emitted in a relatively narrow

In this paper, we estimate the errors of Gaussian transformations implemented using one-way quantum computations on cluster states of various configurations. From all possible cluster state configurations, we choose those that give the smallest computation error. Furthermore, we evaluate errors in hybrid computational schemes, in which Gaussian operations are performed using one-way computations with

We investigate the topological and nontopological photonic states induced by the interchain coupling strength in a one-dimensional coupled circuit quantum electrodynamics chains system. In the case of strong coupling strength, we find that the original topologically nontrivial interface states of the system gradually disappear and finally become two nontopological impurity states. Meanwhile, two new

In the Gaussian-modulated coherent states (GMCS) quantum key distribution (QKD), basis choice is a necessary procedure if homodyne detector is used. However, finite bandwidth of the digital-to-analog convertor (DAC) at the receiver’s side may lead to the imperfection of the basis choice, namely, maybe Bob can not exactly modulate 0 or ##IMG## [http://ej.iop.org/images/1612-202X/17/5/055203/lplab7eb7ieqn1

We present a scheme for generating large-scale W states based on an expansion mechanism in a cavity–quantum dot system. In cases in which the number of particles is even (2 n ), the probability of success will be 1.0. In cases in which the number is odd (2 n − 1), the probability of success will be 1 − 1/2 n . As the number of particles increases, the probability of success is closer to 1. Meanwhile

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Terahertz (THz) frequency sources such as quantum cascade lasers (QCLs) offer a variety of new applications in far-infrared frequency bands. For better understanding of their behavior, a device-specific modeling approach is used to predict the optical output power under current modulation and chip temperature. This letter reports the numerical simulation of gain switching to evaluate temperature dependence

Basic configuration in quantum cryptography is a point-to-point quantum key distribution. In networks with quantum key distribution, the keys received on different network segments are different. For information encryption between arbitrary network nodes it is necessary to have agreement of the keys distributed in different segments of network through a public classical communication channel. The secrecy

A theoretical scheme is presented to realize effective molecular orientation driven by two super-Gaussian pulses (SGPs). As an applied example, the orientation dynamics of LiH molecule is studied by using the time-dependent quantum wave packet method. The calculations are performed including both the molecular vibrational and rotational degrees of freedom. It is shown that the efficient molecular orientation

By solving a two-dimensional time-dependent Schrödinger equation we investigate high-order harmonic generation (HHG) for the ##IMG## [http://ej.iop.org/images/1612-202X/17/5/055301/lplab7be7ieqn2.gif] {$\mathrm{H}_{2}^{+ }$} molecular ion in a circularly polarized laser pulse (CPLP). A comparison is made between a HHG in a CPLP combined with a terahertz (THz) field and with a static electric field