We demonstrate a 2.5 m ring laser with the Ho:YAG and Ho:YLF crystals end-pumped by the Tmdoped fiber laser. In the Ho:YAG laser, the continuous-wave (CW) output power was 4.72 W at a wavelength of 2090.8 nm when the incident pump power was 21.5 W, which corresponded to a slope efficiency of 26.3%. For the Q-switched operation with the 100 Hz pulse repetition frequency (PRF), an output energy of 5

In this study, we measure the output current of a silicon-based positive-intrinsic-negative (p-i-n) quadrant photodetector (QPD) exposed to a millisecond-pulse laser radiation. We study the output current curve for a cell at different laser energy fluences and pulse widths. The results obtained show that the behavior of the output current involves a holding current stage as the photo-generated current

We report on high-power laser-diode (LD) end-pumped Tm:YLF innoslab lasers with different doping concentrations of 2, 2.5, and 3 at.% with a single-end 792 nm LD stack. After series of experiments, we conclude that 3 at.% Tm:YLF lasers can produce a maximum output power of 84.7 W; this value is higher than that of the lasers with two other doping concentrations at the same incident pump power equal

We consider the interaction between two three-level atoms in the Ξ configuration and a quantum system described through SU(1) group algebra operators. To study the quantum phenomena and underlying dynamical behavior, we calculate the wave function of the system. In particular, we investigate collapse and revival phenomena, the correlation function, and the Husimi quasidistribution Q-function.

Luminescence spectra of polytetrafluoroethylene (Teflon), a Teflon film, and a polyethylene film are registered in wide wavelength range under excitation by radiations with different wavelengths. For the first time, we detect two-photon-excited luminescence in polymers at low intensity of exciting light. In Teflon, we also register luminescence in the blue range under excitation by ruby laser pulses

Thin film of oriented crystalline intrinsic polysilicon films were grown on alkali-free borosilicate glass substrate using hot-wire chemical-vapor-deposition (HWCVD) technique. A layer as a source of phosphorus dopant on top of intrinsic polysilicon films were introduced in two different approaches: (i) spinon one-micrometer-thick phosphorus dopant and (ii) phosphorus ion implantation. We investigate

In this paper, we provide the laser-induced breakdown spectroscopic (LIBS) analysis of copper under the action of the ultrafast picosecond Nd:YAG laser and the specifications calculated from the electron temperature of plasma generated by the fundamental (1064 nm), second (532 nm), third (355 nm), and fourth (266 nm) laser harmonics. In this work, a laser pulse energy of 60 mJ±5% with a duration of

In this paper, we show that the energy spectrum of a qudit system (spin-j, N-level atom) with Hamiltonian N×N matrix H is determined by the equation for eigenvalues of the N2×N2 matrix ℋ and its eigenvectors | p⟩ with components, which are probability distributions identified with quantum states in the probability representation of quantum mechanics. We derive this equation based on the conventional

In spatial division multiplexing (SDM)-based communication systems, each spatial mode can act as an independent information-bearing carrier capable of scaling the total transmission capacity by several orders of magnitude. It has been reported that in SDM networks the signal amplitude depends upon the optical-path-length (OPL) difference between the various optical modes. In this work, we realize SDM

Oceanic turbulence is one of the important factors that affect the transmission of quantum optical signals in the seawater medium. However, up to now, none research on the influence of oceanic turbulence on the parameters of quantum communication channel is in progress. In order to fill such vacancies, we simulate in this paper the relationship of oceanic turbulence parameters to the optical wave structure

Wave packet fractional revivals appear as manifestation of a multiple interference of various components of a wave packet during its long-time evolution in a bounded system. We study the phenomenon of fractional revivals by means of the time-dependent interference of information entropy density associated with a bound-state wave packet, which exhibits the formation of self-similar structures – quantum

Earlier, in experiments on DD synthesis in a complex plasma of a nanosecond vacuum discharge (NVD) with a virtual cathode, in parallel, a significant experimental database was accumulated on the output of hard X rays from the inter-electrode ensembles, and a certain correlation was established between the specificity of the X-ray yield and the features of the inter-electrode ensembles of nanoparticles

We develop the quantizer–dequantizer formalism for the probability and mean-value representations of qubits and qutrits. In these representations, the elements of symbols of operators are measurable physical quantities. We derive the star-product kernels, which lead to explicit expressions of the associative product of the symbols of the density operators and quantum observables for qubits. The extension

We propose and experimentally demonstrate a simple and stable photonic approach of frequencydoubled triangular-shaped waveform generation. It mainly consists of an integrated polarizationmultiplexing Mach–Zehnder modulator (PM-MZM) and a balance photoelectric detector (BPD). Two PM-MZM sub-modulators work at the maximum transmission point. By properly setting the amplitude of the local oscillator (LO)

We present a chaotic lidar for underwater ranging and three-dimension (3D) imaging applications. The lidar transmitter based on a laser diode with free space optical feedback is designed to generate 520 nm wavelength wideband chaotic signal. This transmitter is used with a correlation-based lidar receiver to perform a ranging demonstration in clean water with a measured attenuation coefficient of 0

X-ray lasers based on transitions in highly-charged Ni-like ions generating in the “water window” wavelength range can be pumped by compact laboratory discharge sources. In this paper, we report the results of numerical simulations of the plasma dynamics and kinetics in an X-ray laser based on transitions in Ni-like xenon ions. The laser active medium is created by an extended low-inductive high-current

We investigate the operating modes of diode lasers in the external cavity scheme of spectral beam combining, using the virtual laser-diode array method. We determine the spectral range of the diode array and the watt–ampere characteristics of a single-diode laser for various wavelengths. We experimentally show that by varying the output coupler transmission with the wavelength, one can optimize the

We consider the implementation of the logical operation of disjunction of signals using accumulated stimulated echo holography. We study the processing of information embedded in the laser pulses of a pulse pair, with one of the pulses in the pair being an object and the other one having a wide frequency spectrum. We show that, taking the pulse spectra as narrow frequency regions within the inhomogeneously

We investigate the first-Stokes operation of YVO4 crystal driven by an acousto-optic Q-switched Nd:YAP laser with X(ZZ)X Raman configuration. The fundamental wavelength laser operation by Nd:YAP crystal was at 1080 nm corresponding to the first-Stokes wavelength at 1195 nm based on the Raman shift of 890 cm−1 in a-cut YVO4 crystal. Under an incident pump power of 8 W and a pulse repetition frequency

We investigate increase in the surface temperature of biased Si avalanche photodiodes (APDs) fabricated in an external capacitor circuit irradiated by a millisecond-pulse laser. The results obtained show that different external capacitance parameters have different effects on the temperature rise, the smaller the capacitance of external capacitor, the lower surface temperature increase in the APD.

In this work, we demonstrate a passively-Q-switched 1.33 μm Nd:Lu2YSc1.5Ga3.5O12 (Nd:LuYSGG) laser based on the Bi2Se3 topological insulator (TI) as a saturable absorber (SA). We obtain pulse widths as low as 146 ns at a pulse repetition rate of 349.5 kHz and a pulse energy of 1.03 μJ, which provides a peak power of 7.05 W. These results represent some of best yet published in terms of repetition rate

We design a high-sensitivity optical-fiber sensor for measurements of displacement and refractive index based on dual-coating-stripped loop-shaped single-mode fibers. For this, we produced two unrelated interference dips as a consequence of different radii of two loop-shaped fibers. Since loop-shaped optical fibers are assigned different tasks at the same time, the two dips present their own characteristics;

In this paper, we propose a three-dimensional (3D) integral image display method that uses the similarity of corresponding points in a series of axially recorded images. First, we calculate the corresponding points of a 3D object, in view of the proportional relationship of the distances of points in the elemental images collected, using axially distributed sensing (ADS). Next, we extract the depth

We study the emission spectrum and quantum-state fidelity for an atomic system interacting with radiation fields of quantum systems described by power-law potentials. We consider a set of manifold fields that are characterizable by their level-energy differences. They include triangular, infinite, and harmonic potentials as special cases. We present the time evolution of the spectrum and fidelity for

We derive the analytical expression of the probability density of orbital angular momentum modes for elegant and standard Laguerre–Gaussian beams in turbulence. The results show that we can increase the initial topological charge of the beams to reduce the detrimental mode crosstalk induced by the turbulence. We also discuss the influence of the beam parameters on the probability of signal and the

We study the employment of an adopted optics system for the reduction of thermal blooming effects by the phase correction of a 1.064 μm laser. The energy concentration of the beam spot in the farfield substantially increases if the adaptive optics system is performed in a closed loop. The phase compensation of the adapted optics system is effective for a Bradley–Hermann distortion number of less than

We present quantum formula for extropy based on the Husimi Q-function and the atomic Husimi Q-function. The quantum extropy is used to detect the entanglement or nonlocal correlations of the system consisted of a single qubit and the radiation field. We provide explicit forms of the binomial and even binomial distributions. We compare the temporal behavior of quantum extropy within the atomic and field

Based on the finite-difference-time-domain method and the plane-wave method, we study the imaging performance of two-dimensional hexagonal-structure photonic-crystal flat panel lens. First, the plane wave expansion method is used to verify that the structure has a negative refraction effect. The equivalent refractive index is – 1 when the normalized frequency is 0.251. The finite-difference-timedomain

The passively Q-switched (PQS) operation of a Tm:YAP laser was experimentally demonstrated with an MoSe2 saturable absorber (SA). In the PQS mode, an average output power of 1.084/1.744 W with a pulse width of 686.0/1222 ns at 196.5/177.7 kHz was acquired from Tm:YAP laser under an output couple (OC) with transmittances T of 2%/5%, corresponding to an optical–optical conversion efficiency and an output

We present a passively Q-switched Ho:Sc2SiO5 microchip laser with a molybdenum disulfide saturable absorber for the first time. The molybdenum disulfide materials are fabricated on the end surface of a microchip Ho:SSO crystal. The physical length of the laser cavity is only 3 mm. Three output couplers with different transmissions are utilized to test the passively Q-switched laser performance. The

We report a stable high-power all-solid-state Q-switched laser operating at 294.6 nm with a pulse width of 24 ns and a repetition rate of 20 kHz produced by intracavity sum-frequency generation and external frequency doubling in LiB3O5 and β-BaB2O4 crystals, respectively. Upon synchronizing the fundamental lasers, the maximum output power at 589 nm is 1.2 W, which is frequency doubled to produce up

We design a competent gain-flattened and noise figure in L-band hybrid optical amplifier using a hybrid configuration with a Raman amplifier (Raman) and quantum-dot vertical-cavity semiconductor (QDVC-SOA) for a 400×20 Gbps super-dense wavelength division multiplexing system (SD-WDM) at channel spacing 100 GHz. The proposed hybrid optical amplifier (HOA) shows that it can be constituted into an optical

We demonstrate a 355 nm ultraviolet nanosecond laser produced by the type I phase-matched frequency doubling in a K3B6O10Br (KBOB) nonlinear optical crystal. The use of 5022 μJ, 710 nm pump pulses at 10 Hz repetition rate produces 4.273 ns, 355 nm, 717 μJ pulses that corresponds to a frequency doubling conversion efficiency of 14.3%. The energy instability of the frequency-doubled pulse train measured

For the first time, we present a passively Q-switched 1060 nm Nd:GSAG laser using a two-dimensional molybdenum disulfide (MoS2) nanosheet as saturable absorber. We investigate in detail the output characteristics of this laser such as average output power, pulse repetition rate, pulse width, pulse energy, and pulse peak power.

A polycrystalline diamond film is grown on a 2 inch Si substrate using a microwave-plasma chemicalvapor-deposition technique. The high quality of the diamond films is confirmed by Raman spectra. A multiple-step procedure is used for local etching of the substrate to form the pattern of an array of 50 diamond membranes with the diameter in a range from 150 to 300 μm. The morphology of the membranes

In this paper, we give an overview of nonclassical effects, such as squeezing and sub-Poissonian states, of an optical field in coherent anti-Stokes Raman scattering and coherent anti-Stokes hyper-Raman scattering under the short time scale. We establish the coupled Heisenberg equations of motion of quadrature operators in terms of real and imaginary parts. We investigate the photon statistics of the

For the first time, we obtained the photoreflectance spectra in single-layer samples of porous silicon with 13 μm thick in the 550–1000 nm spectral region. To describe the observed reflection and photoreflectance spectra, we use a theory of multiple-beam interference, taking into account the strong absorption of Si in this spectral region. We show that, under the action of a laser radiation with a

The electron density distribution and average electron temperature distribution in reactive ion etching (RIE) chamber are of great significance for the ionization and excitation reaction rate. The uniformity of radial distributions of the electron density and average electron temperature in the discharge chamber greatly affects the uniformity of the etching, especially the plasma etching of large area

Two superconducting (SC) qubits interacting with a radiation field in the coherent state (CS) in the presence of Stark shift are investigated. The density matrix is expressed in terms of the wave function to describe the proposed system. Physical properties, such as the geometric phase, linear entropy, and negativity are used to describe the behavior of the system. The effects of the Stark shift and

We investigate dynamics of quantum entanglement (QE) and quantum Fisher information (QFI) of a system of two four-level atoms moving in the thermal environment. The time evolution of the state vector of the whole quantum system interacting with the thermal field is investigated numerically in the presence of intrinsic decoherence (ID). We see that ID and the thermal environment play a prominent role

To date, it is a common knowledge that there exists two kinds of turbulence in Earth’s aerosphere, the Kolmogorov turbulence and the non-Kolmogorov turbulence, which has been confirmed by both increasing experimental evidences and some results of theoretical investigations. Therefore, it is necessary to further develop theory of optical wave propagation through the atmospheric turbulence, namely, to

We consider coherent dynamics of cold atoms in a square optical lattice without interference between counter-propagating laser beams. The dynamics is treated within the framework of semi-classical approximation, taking into account a coupling between the atom internal and external degrees of freedom. The corresponding set of equations of motion has been found before to be regular or chaotic in dependence

We investigate the multiphoton coherence effects on two weak probe-beam transitions in a five-level double-inverted Y system, where the two probe transitions are also affected by phase-dependent χ(3) processes occurring via Λ and Ξ channels. This system provides two channels to create each two-photon coherence and three-photon coherence. We show that quantum interference induced by the closed loop

We carry out the experimental study on Brillouin erbium fiber laser in two different structure configurations. In the first configuration, Brillouin pump laser directly stimulates the Brillouin scattering light, whilst in the second it gets pre-amplification before stimulating the Brillouin scattering light in silica optical fiber. Employing distributed-feedback fiber laser as the Brillouin pump laser

We propose and experimentally demonstrate a novel and simple approach to implementing optical single-sideband (OSSB) modulation with tunable optical carrier-to-sideband ratio (OCSR) based on a dual-polarization Mach–Zehnder modulator (DPol-MZM) and a polarizer (Pol). In this scheme, the light wave is modulated by radio frequency (RF) signal with SSB modulation in the upper arm of the DPol MZM, while

We study theoretically and experimentally superradiant dynamics in multiple-section GaAs/AlGaAs laser structures. We develop a model based on the one-dimensional Maxwell curl equations without making use of the slowly-varying envelope approximation and demonstrate that strong transient periodic modulation of both e – h density and refractive index drastically affect the dynamics of emission generation

Despite their recognized merits in terms of discrimination, compactness, and robustness, chord-length shape features have not received a great deal of attention in the literature on license plate recognition. In this paper, we present an innovative k nearest neighbors (kNN) approach for license plate detection and recognition, where a new low-dimensional descriptor that incorporates shape information

We investigate the possibility of improving the reconstruction accuracy of electron density distributions ne(r) for plasma objects with a complex structure by processing the results of combined interferometry and schlieren photography. We carried out the numerical simulations for a spark channel with a micrometer-sized diameter developing in atmospheric air. We show that the data obtained from the

Undoped and aluminum-doped ZnO (AZO) thin films were prepared by the sol–gel process. Single thin layers were synthesized at room temperature by spin coating on glass and silicon substrates. The gel was laser irradiated (530 nm, 10 W) during the spinning process. We used Fourier-transform infrared (FTIR) spectroscopy and scanning electron microscopy (SEM) to characterize the chemical bonding configuration

The eye is the most important sensory organ of the human body, and the cornea and anterior chamber are very important components In surgeries like vision correction, it is necessary to know the accurate corneal thickness and anterior chamber depth of human eyes. Their accurate measurement cannot only provide a reference for doctors, but also provide a strong guarantee of surgical results. In order

As a bridge between crystal and fiber, the single crystal fiber (SCF) can combine the advantages of the two materials and show great potential in high-power lasers. In this paper, we select a Nd:YAG SCF as the gain medium in a diode-end-pumped linear cavity. The Nd:YAG SCF with the dimensions of ∅ = 1 mm × 50 mm was manufactured using the micro-pulling-down technique. At an incident pump power of 153

In this paper, within the framework of classical electrodynamics, we rederive in a simple way the formula for the cross section of light scattering by a moving particle. The results are of interest for the community of researchers working on laser-electron X-ray generators.

The three-dimensional microsolid can be fabricated by scanning point-by-point inside the polymer material according to the predetermined trajectory in femtosecond-laser two-photon direct writing mode. In the process of machining, the shape and intensity distribution of focus spot are changed by some processing parameters, which affect the processing accuracy and surface quality. Based on Fresnel diffraction

We demonstrate a synchronously self-Q-switched and self-mode-locked output pulse fiber laser based on a linear compound resonator and an LD cladding-pumped Yb-doped double-clad fiber. A maximum average output power of 332.1 mW is achieved. We observe that the maximum pulse envelope width is 8 μs, and the pulse energy is 3.83 μJ for the self-Q-switched pulse envelope. At the same time, the achieved

Electric quadrupole interactions are normally weak but are shown capable of being exploited once the neutral atom interacts at near resonance. The physical model used here is based on evanescent Hermite–Gaussian light in a vacuum being total-internally reflected at the planar surface of a dielectric. The resulting optical quadrupole potential distribution is restricted to a subwavelength region near

Synthetic aperture imaging systems can be applied to equivalently get high-resolution images of traditional monolithic primary mirror systems with less weight and costs. Spatial modulation diversity (SMD), a newly developed post-processing technology applicable for such synthetic aperture systems, is very sensitive to Gaussian noise, which greatly limits its further application. In this paper, we propose

In this communication, we consider a pair of entangled quantum systems, each described by the su(1) Lie algebra, interacting with two two-level atoms. We discuss in detail the influence of the detuning terms on the system and derive from the Heisenberg equations of motion the expressions of various operators corresponding to the dynamics. Solving the associated Schrödinger equation, we obtain the general

We propose a method for low-concentration detection of sodium chloride based on surface plasmon resonance (SPR). A novel prism coupling structure is designed for the sodium chloride concentration sensor, where a TiO2–ZnO composite film and a MoS2–GO hybrid nanosheet are chosen to enhance the surface plasmon resonance based on an Au nanowire array because of their unique properties in metal nanowire

Glauber coherent states of quantum systems are reviewed. We construct the tomographic probability distributions of the oscillator states. The possibility to describe quantum states by tomographic probability distributions (tomograms) is presented on an example of coherent states of parametric oscillator. The integrals of motion linear in the position and momentum are used to explicitly obtain the tomogram

We realize the Landau–Streater (LS) and Werner–Holevo (WH) quantum channels for qutrits on IBM quantum computers. These channels correspond to the interaction between a qutrit and its environment that results in the globally unitarily covariant qutrit transformation violating the multiplicativity of the maximal p-norm. Our realization of the LS and WH channels is based on embedding the qutrit states