A high pulse energy vacuum ultraviolet (VUV) 177.3 nm nanosecond (ns) laser generated from the sixth harmonic generation of an ns 1064 nm laser (10 ns, 10 Hz) was reported. Firstly, a frequency tripled UV pulse energy of 21.35 mJ at 355 nm was obtained with a pulse duration of 5 ns at a pump pulse energy of 150.6 mJ at 1064 nm. By a KBe 2 BO 3 F 2 (KBBF) prism coupled device containing a 1.6 mm thick

A linear cavity picosecond Er-fiber laser, which was passively and harmonically mode-locked with SESAM, is demonstrated. The advantage of the proposed configuration is the fast tuning of the pulse repetition rate in the range from tens of MHz to 1 GHz, realized by varying the pump power without any additional adjustment of the polarization.

The frequency conversion of Ti:Sapphire laser second harmonic pulses into two-color emission using a tandem of BaWO 4 Raman crystals was experimentally demonstrated with an internal efficiency of ∼17%. The output emission contained symmetrical Stokes and anti-Stokes spectral components separated by 902 cm −1 with a full-width half-maximum bandwidth of ≥110 cm −1 each. The applicability of this two-color

We show that the quality of the underwater imaging can be effectively improved by utilizing the computational ghost imaging (CGI) scheme with shaped Lorentz sources. The formula for the point-spread function in the underwater CGI system with a shaped Lorentz source is derived theoretically, and numerical examples are given to see how the CGI quality can be affected by the oceanic turbulence, including

In this work, we suggest a new algorithm for plotting the singularity lines of an electromagnetic field, which uses its derivatives in a certain area of space and the position of a single point belonging to an unknown singularity line. This algorithm is based on the common properties of rationally parameterizable curves. The implementation of this method is capable of plotting these lines significantly

Quantum tomography is a process of quantum state recognition with multiple measurements. An essential goal for the quantum tomography algorithm is to find measurements that will maximize the useful information about an unknown quantum state obtained through measurements. One of the recently proposed methods of quantum tomography is the algorithm based on rank-preserving transformations. The main idea

We offer and demonstrate a new type of plasmonic metasurface for sensorics and surface-enhanced Raman spectroscopy (SERS) spectroscopy, characterized by a wide spectral range of sensitivity from 450 nm to 850 nm. The metasurface is formed by Ag nanoparticles of different sizes. The metasurface has clear anisotropy formed by the Ag nanoparticles’ size-dependent plasmonic resonances. The resonant wavelength

With the overwhelming success in the field of quantum computing, much attention has been paid to constructing a quantum neural network by combining a classical neural network with quantum computing. In this paper, we propose a novel quantum neural network model based on a quantum version of the sigmoid function, which skillfully combines the non-linear dissipation dynamics of neural computation with

We investigate the distributions of quantum coherence characterized by superadditivity relations in multipartite quantum systems. General superadditivity inequalities based on the α th ( ##IMG## [http://ej.iop.org/images/1612-202X/17/10/105207/lplabae02ieqn1.gif] {$\alpha\geqslant 1$} ) power of l 1 norm of coherence are presented for multiqubit states, which include the existing ones as special cases

The ultrasonic characterization of the propagation of femtosecond laser pulses in pure transparent water and colored phenol-red dye solutions at variable concentrations indicates their thermoacoustic pressure generation due to intrinsic multi-photon absorption in the low-power sub-filamentation regime and sub-linear pressure response of sub-critical plasma via free-carrier absorption in the filamentation

We report here the low-loss double-end coupling of an anti-resonant hollow-core fiber (AR-HCF) with a solid-core single-mode fiber by the fiber tapering technique for the first time. The double-end coupling model is established by the beam propagation method, and the various influences, such as those of insertion depth, tapered waist offset, tapered waist bending, etc, on the coupling efficiency are

This study aimed to evaluate the method of fluorescence diagnostics using the developed video-fluorescent equipment with laser excitation of fluorescence and the assessment of the effectiveness of photodynamic therapy via the photobleaching of the chlorin e6. The boundaries of precancerous conditions and cervical neoplasms were established using video-fluorescent diagnostics and then clarified using

The multiple optomechanically induced transparency (OMIT) of a compound optomechanical system is studied. The system contains two distant cavities and one of the cavity is filled with a three-level atomic medium. We focus on the number of OMIT windows, which is influenced by the coherent interactions between the system components. We find that four transparency windows can be observed from the output

We studied the effect of optical clearing (OC) by glycerol, Omnipaque TM (iohexol), and polyethylene glycol on human skin in vivo using a portable Raman spectroscopy system. Kinetic curves were determined for different concentrations of these optical clearing agents (OCAs). The three agents enhanced OC, showing non-monotonic behavior for serial concentrations. The dehydration mechanism also caused

In this work, laser-induced plasma transmission spectroscopy (LIPTS) was employed to evaluate the low water content in crude oil emulsion by applying a 248 nm ultraviolet laser. The peak of the LIPTS signal (V P ) decreased with the water content C W increasing from 0 to 0.3%. V P increased monotonically as C W increased from 0.3% to 0.5%, and decreased again above C W ∼ 0.5%. One probable mechanism

Stimulated low-frequency Raman scattering (SLFRS) with a maximum efficiency conversion of up to 50% was registered in a water suspension of silica nanoparticles. The dispersion relations of the SiO 2 spheres’ acoustic modes in the surrounding water and the damping parameters were estimated. The experimentally obtained SLFRS frequency shift corresponding to the nanoparticles’ acoustic eigenfrequency

We introduce a new unconditionally solvable level-crossing two-state model given by a constant-amplitude optical field configuration for which the detuning is an inverse-square-root function of time. This is a member of one of the five families of bi-confluent Heun models. We prove that this is the only non-classical exactly solvable field configuration among the bi-confluent Heun classes, solvable

We propose a scheme whereby we optimized the driven pulses applied on qubits to realize fast and robust population of quantum state transfer and entanglement generation between four superconducting flux qubits based on adiabatic passage. The quantum state was transferred from one qubit to another directly with high fidelity through applying an inverted set of pulses. Moreover, the resident time of

We study theoretically the action of subcycle unipolar pulses on the rotational dynamics of polar molecules. We show that efficient excitation of molecular rotational resonances by subcycle pump pulses with respect to bipolar single-cycle one is achieved, provided that duration of excitation pulses is much smaller than the rotational period of the molecule. The excitation probability for different

Based on the quantum-memory-assisted entropic uncertainty relation (QMA-EUR), we study the quantum phase transition (QPT) of a spin-1/2 frustrated Heisenberg chain and show that QMA entropy can be a useful tool to detect QPT. For the six-site case, we choose the reduced two-site as the detecting system and obtain the analytical result of QMA entropy and its bound. We find that the QMA entropy of the

Quantum entanglement is important quanum resources in quantum information sicence. Here we propose an approach to preparing atomic quantum entanglement in a hybrid atom-cavity-fiber system. Using quantum Zeno dynamics method, the system evolution states are always split into a series of Zeno invariant subspaces consisting of dark and bright states. By choosing the initial state of the system, the bright

Proportion-integral-derivative (PID) closed-loop frequency-locking (CLFL) technology has been demonstrated to improve the magnetic field sensitivity of spin-based sensors based on the nitrogen-vacancy (NV) color centers in diamond. First, we analyse the undulation effect of the fluorescence quantum yield of NV centers with a magnetic field. The valley value of the magnetic resonance spectrum have been

The minimum time a system needs to change from an initial state to a final orthogonal state is called the quantum speed limit time. The quantum speed limit time can be used to quantify the speed of the quantum evolution. The speed of the quantum evolution will increase, if the quantum speed limit time decreases. In this work, we will use a relative purity-based bound for the quantum speed limit time

The COVID-19 pandemic has updated research on inactivation of coronaviruses with physical, chemical, and physical-chemical treatments. The review focuses on the inactivation of coronaviruses including the recent SARS-CoV-2 and viruses of other groups with analogous structure using optical radiation. The antiviral effects of different optical ranges from vacuum ultraviolet to infrared radiation are

Based on the Heisenberg uncertainty relation and the entropy uncertainty relation, the nonclassical effects described by variance squeezing and entropy squeezing for a two-level system driven by a classical phase noisy laser are investigated. Analytical expressions of the variance squeezing and entropy squeezing subjected to the classical phase noisy laser are derived. Our results show that the nonclassical

We demonstrate the three-dimensional localization of a single nitrogen-vacancy (NV) center in nanodiamond by the use of position-dependent standing-wave laser fields in an external magnetic field. We show that various localization phenomena including cask-like, disc-like, cylinder-like, and sphere-like patterns can be achieved by monitoring the probe absorption spectrum in two different coupling formalisms

We present a high-power single-frequency continuous-wave (CW) 671 nm laser by the second-harmonic generation (SHG) of a 1342 nm laser based on an external bow-tie enhancement cavity. Different from previous works, and using periodically poled nonlinear crystals for the SHG, we adopt the high damage-threshold nonlinear crystal lithium triborate (LBO) in the external SHG cavity to achieve a high-power

The experimental measurement of the R(18), R(20), R(22), R(24), R(26), R(28), R(30), R(34), R(36) absorption lines collision broadening for the 12 C 16 O 2 molecule vibrational band 20013–00001 and P(10), P(12), P(14), P(16), P(18), P(20), P(22) absorption lines for the 13 C 16 O 2 molecule 20012–00001 vibrational band have been reported in this paper. The research has been first carried out by the

Heart Failure is a major component of healthcare expenditure and a leading cause of mortality worldwide. Despite higher inter-rater variability, endomyocardial biopsy is still regarded as the standard technique, used to identify the cause (e.g. ischemic or non-ischemic cardiomyopathy, coronary artery disease, myocardial infarction etc) of unexplained heart failure. In this paper, we focus on identifying

Remotely preparing quantum states, which possess some desired features, is an important task for future quantum network host providers. On the other hand, the non-degenerate discordant two-qubit states, the states with different left and right quantum discords, is necessary for the implementation of some quantum information and quantum computation processes. This paper presents a new preparation scheme

The measurement precision for two incompatible observables in a typical quantum system can be improved by the aid of one particle as a quantum memory. In this work, we study the entropic uncertainty relation in the presence of quantum memory (EUR-QM) and dense coding capacity (DCC) for arbitrary two-qubit X-states, and then we obtain an explicit relationship between the lower bound of the uncertainty

Both quantum-electrodynamical (QED) and semiclassical approaches are applied to study the spontaneous emission of an atom or atomic ensemble driven by the strong external laser field. It is demonstrated that the semiclassical approach typically used for analyzing the emission of dressed atomic systems is inconsistent with the QED approach and does not provide a proper description of the emission of

We propose and demonstrate a new type of Yb-doped fiber called spindle-shaped core ytterbium-doped fiber (SSCYDF) and conduct a laser oscillator based on this fiber. The SSCYDF is a kind of long tapered fiber which consists of a small-core section at both ends and a large-core section in the middle. The ratio of core/clad diameter remains a constant along the total length of the SSCYDF (∼31 m). The

We report on the experimental observation of a type of parametric spectral sideband generation in a continuous wave (CW) fiber laser operating in the normal dispersion regime. The appearance of the sidebands is a threshold effect and their spectral shifts from the CW wavelength vary with the cavity length and CW power. We show that the sideband formation is induced by the periodic power variation of

Coulomb-corrected strong-field approximation (CCSFA), which integrates Coulomb potential and the interference effects, is a semiclassical method successful in the study of atomic strong-field ionization. However, it is difficult to numerically solve the saddle-point equation describing tunnelling in the CCSFA, especially for complex laser fields such as elliptically or orthogonally polarized two-color

Polarization investigation of the emission spectrum of Nd ions at the 4 F 3/2 → 4 I 11/2 transition in the b-cut Nd 3+ :YAlO 3 crystal showed that this gain medium is promising for multiwavelength laser operation. A diode-pumped continuous-wave Nd 3+ :YAlO 3 laser with an intracavity retardation plate and a dichroic output coupler demonstrated dual-wavelengths operation at 1064.5 & 1072.6 nm and 1072

A Q-switched S-band fiber laser based on a thulium-fluoride fiber gain medium and copper telluride (Cu 2 Te) based saturable absorber (SA) is demonstrated. The Cu 2 Te based SA is fabricated as a thin film and at the maximum pump power, the generated Q-switched output has a minimum pulse width of 3.2 µ s and highest pulse energy of 56.7 nJ. The pulse train varies from 20.9 kHz to 30.2 kHz at the highest

Micro/nanoparticles contamination is one of the key factors affecting the quality of precision manufacturing, and the traditional cleaning methods cannot function effectively. The laser plasma has high temperature and pressure, which can be used as a new and potential method to implement the removal of micro/nanoparticle, and it has become the focus of attention. This paper aims to analyze the particles

The propagation of a spatiotemporal soliton in a focusing quadratic-nonlinear waveguide is theoretically investigated. This soliton is a bound state of localized bunches of light energy at the fundamental frequency and at its second harmonics. It is shown that with anisotropic spatial distribution of the refractive index in the cross section of the waveguide, the soliton trajectory can be a spatial

The non-local advantage of quantum coherence (NAQC) is regarded as a quantum correlation, which can be reflected by the violation of a set of inequalities based on various coherence measures. In this work, we explore the NAQC and Bell nonlocality (BN) in a two-qubit Heisenberg XYZ model. The results show that one can capture the BN in the case of both anti-ferromagnetism and ferromagnetism. By contrast

The optical cryptosystem based on equal modulus decomposition (EMD) has attracted wide attention due to its remarkable anti-attack characteristics. In this paper, we propose a novel fully convolutional network model, which is an end-to-end deep learning method, to attack the EMD-based cryptosystem. The trained network model can retrieve plaintext after inputting many ciphertext-plaintext pairs and

In this paper we present for the first time the 2.3 µ m thulium doped tellurite glass fiber laser with practically significant output parameters. The 200 mW average and 400 mW peak output powers at 2.3 µ m were obtained using a 30 cm long fiber pumped by a 794 nm fiber coupled commercial laser diode.

We show that the density of states and gain spectra of InGaAs/GaAs quantum well-dot (QWD) hybrid nanostructures qualitatively differ from that of quantum wells (QWs) and quantum dots. In QWDs, the density of states does not increase to higher energies and ground-state lasing is maintained up to shorter cavities (higher output loss) as compared to QW lasers emitting in the same optical range. The QWD

In this work, the transverse mode instability (TMI) behaviors in high-power all-fiber laser oscillators based on the ytterbium (Yb)-doped fiber (YDF) with a core diameter of 30 μ m have been experimentally investigated for the first time. We have constructed all-fiber laser oscillators with the YDF with core/inner-cladding diameter of 30/400 μ m and 30/600 μ m, and investigated the corresponding TMI

We report here for the first time, to the best of our knowledge, a direct laser diodes pumped 5 kW 1080 nm fiber amplifier using chirped and tilted fiber Bragg gratings (CTFBGs) to suppress stimulated Raman scattering (SRS). With one or two CTFBGs, which are carefully designed and fabricated to match the Raman gain spectrum, inserted between the seed and the amplifier stage, effective SRS suppression

We demonstrated an all fiber passively mode-locked fiber laser by using one single mode fiber-graded index multimode fiber-single mode fiber (SMF-GIMF-SMF) structure as a saturable absorber (SA) based on the nonlinear multimode interference. The proposed SA with the modulation depth of 9.58%, saturation intensity of 36.50 MW cm −2 and nonsaturable loss of ∼ 21% was inserted into an Er-doped fiber laser

MXenes have recently gained significant research interest due to its graphene-like structure that allows for a multitude of applications such as electronics, batteries and optics to be realized. In this work, stable Q-switched pulses are passively obtained from a thulium-doped fiber laser using an MXene Ti 3 C 2 T X coated microfiber as a saturable absorber (SA). The generated pulses have center lasing

Rare-earth-doped single-crystal fibers are promising for use in developing high-power lasers due to their improved thermal management and excellent optical properties. In this work, Er-doped CaF 2 single-crystal fibers of good optical quality were successfully grown by a modified temperature gradient technique method. For the characteristic clustering effect of trivalent rare earth ions within fluorite

This paper presents the results from the generation of elliptical high harmonics in a process of two-color elliptical laser field interaction with a single atom. Numerical simulations are performed for different values of ellipticities of the two-color driving laser field (the fundamental and the second harmonics of the Ti:Sapphire laser), together with their relative helicity. The dependency of the

The propagation of a few-cycle Laguerre–Gaussian (LG) beam through polar molecular media as well as the accompanied harmonic radiation is theoretically investigated under the condition of two-photon resonance. The results show that a second-order harmonic vortex harmonic occurs due to the inversion symmetry breaking of polar media, which is obviously enhanced during nonlinear propagation as a consequence

Electro-optic sampling of pulsed terahertz radiation by femtosecond laser pulses in noncollinear geometry in a 40 μ m thick layer of LiNbO 3 attached to a Si prism is experimentally demonstrated. Terahertz radiation is prism-coupled into the layer through its surface and modulates the frequency and angular spectra of the optical radiation propagating along the layer as a fundamental mode of a dielectric

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