诱导式受激布里渊散射相位共轭腔

The theory of ultrafast nonlinear interferometer which is a single-arm interferometer based on a semiconductor laser amplifier is described in Jones matrix. The device is suitable to be a demultiplexer in future optical time-division-multiplexing systems, which utilizes the phase shift induced by the refractive index nonlinearities of SLA.     

Investigation of negative ion states in HCl and HF by configuration interaction methods

Multi-reference configuration interaction calculations are employed for the study of Born-Oppenheimer potential energy curves in HF/HF^- and HCl/HCl^-. Large gaussian basis sets including negative ion functions as well as diffuse s, p and d AOs are employed thereby. In HCl^- a repulsive 2Σ⁺ state emerges from the calculations approximately 4·2 eV above the HCl X ¹Σ⁺ ground state; no such entity could be observed in HF^- in the energy range treated. All other CI roots which produce potential curves parallel to and above the X ¹Σ⁺ curve are found to possess quite diffuse charge distributions in the basis set variations undertaken and can therefore not be considered resonant states but rather as discrete representations of free-electron species in the HX + e^- continuum. For large internuclear distances the HF^- and HCl^- curves lie below those of the neutral species, whereby the crossing between the X ²Σ⁺ ionic and X ¹Σ⁺ curves are calculated to occur at 3·2 a ₀ in HCl/HCl^- and 2·6 a ₀ in HF/HF^-. Finally it is argued that non-adiabatic effects involving the low energy HX^- continuum states in the Born-Oppenheimer approximation and the bound HX^- species at large internuclear separations (with continuation inside the HX potential well) are ultimately responsible for observed electron scattering resonances, in accordance with recent work of Domcke and Cederbaum and of Nesbet.     

输入光特性对超快非线性干涉仪开关窗口的影响

就超快非线性干涉仪(UNI)的输入光特性对其开关窗口的影响进行了数值模拟和实验研究,输入光包括控制光脉冲和探测光脉冲。在数值模拟中,调节控制光脉冲和探测光脉冲的功率及脉宽,功率越高和脉宽越窄,窗口的形状越好。在调节过程中发现控制光脉冲和探测光脉冲都存在一个最佳的功率点使窗口的形状达到最优。如果继续增大控制光脉冲功率,会使窗口的顶部倾斜,窗口形状恶化;而继续增大探测光脉冲功率,窗口的消光比开始下降。在数值模拟的基础上进行了10Gb／s的超快非线性干涉仪全光开关实验,在实验中用连续光代替探测光脉冲以观察窗口形状。通过改变控制光脉冲和连续光功率来验证它们对超快非线性干涉仪开关窗口的影响。实验表明,应选用短而强的控制光脉冲和最优功率点的连续光,这与模拟结果吻合。     

Characterization and optimization of SOA-based UNI recirculating shift register switching window

The operation of an all-optical recirculating shift register implemented with the semiconductor optical amplifier (SOA)-based ultrafast nonlinear interferometer (UNI) in a counter-propagating, inverting configuration is methodically studied and analyzed. This is achieved by applying an appropriate model for a SOA deployed as the nonlinear element in an interferometric switch driven by ultrafast and strong feedback optical pulses. By means of numerical simulation the impact of the critical functional parameters on the formation of the switching window is thoroughly investigated and assessed enabling to provide useful design rules for their proper selection and combination so as to optimize the specific metric and ensure high performance. The undertaken theoretical treatment can be extended for characterizing other more complex all-optical circuits and subsystems of enhanced functionality that employ this type of shift register as the key building module.     

Performances of Switching Window of Ultrafast Nonlinear Interferometer (UNI) Demultiplexer

In this paper, the theoretical model of the UNI is proposed in detail, which counts on the ultrafast nonlinearities and longitudinal effects of semiconductor optical amplifier (SOA). The transfer function of UNI is also obtained. The switching window, which is a key parameter for demultiplexer, is then analyzed. It's shown that the switching window properties are determined by the length of SOA, the length of the birefringence fiber (BRF), and the parameters of control pulses such as control pulse energy, pulsewidth, power.     

Investigation of surface plasmon resonance using cylindrical dielectric-metal-dielectric (C-DMD) plasmonic configuration

In this paper we have proposed a technique based on image analysis of the surface plasmon excitation at the metal-dielectric interface of inside silver coated fused silica capillary glass tube. Chemical deposition technique has been used for the deposition of silver. Angular interrogation in Kretschmann-like configuration is realized by non-radial transverse illumination of this cylindrical dielectric-metal-dielectric (C-DMD) structure with a He–Ne laser source. Here the uniform film deposition of the inside surface of the capillary is not that crucial except within the transversely illuminated working area concerned. Moreover, the proposed technique has been validated experimentally for sensing different aqueous dielectric samples inserted inside the tube.     

Motion of a neutron in a magnetic field of special configuration

It is shown that the neutron can have bound states in a magnetic field of special configuration.     

Quadratic solitary waves in a counterpropagating quasi-phase-matched configuration

We demonstrate the possibility of self-trapping of optical beams by use of quasi phase matching in a counterpropagating configuration in quadratic media. We also show the predominant stability of these beams and estimate the power level required for their observation.     

Multiplexing of fiber-optic acoustic sensors in a Michelson interferometer configuration

A new multiplexing method demonstrating the separation of two series of geometrically arranged fiber-optic distributed sensors in a Michelson interferometer (MI) configuration has been developed. This method can acquire data from two sensors, then propagate the data into one channel, and finally separate the data by determining their working point, which is essential for some remote measurements. The working point of one sensor was deflected from the normal MI by introduction of two reference arms. The deflection was extracted electrically and employed to label the sensor. Verification with commercial piezoelectric transducers proves the efficiency of the method.     

Graphene-based Q-switched pulsed fiber laser in a linear configuration

A pulsed laser system is realized with graphene employed as a Q-switch.The graphene is exfoliated from its solution using an optical deposition and the optical tweezer effect.A fiber ferrule that already has the graphene deposited on it is inserted into an erbium-ytterbium laser(EYL)system with linear cavity configuration.We successfully demonstrate a pulsed EYL with a pulse duration of approximately 5.9μs and a repetition rate of 20.0 kHz.     

Long distance quantum teleportation in a quantum relay configuration

A long distance quantum teleportation experiment with a fiber-delayed Bell state measurement (BSM) is reported. The source creating the qubits to be teleported and the source creating the necessary entangled state are connected to the beam splitter realizing the BSM by two 2 km long optical fibers. In addition, the teleported qubits are analyzed after 2.2 km of optical fiber, in another laboratory separated by 55 m. Time-bin qubits carried by photons at 1310 nm are teleported onto photons at 1550 nm. The fidelity is of 77%, above the maximal value obtainable without entanglement. This is the first realization of an elementary quantum relay over significant distances, which will allow an increase in the range of quantum communication and quantum key distribution.     

Multiple solutions in configuration space in a chiral nuclear model

A saturatinf chiral lagrangian allows for two different types of nuclear structures: strongly bound shell like nuclei and weakly bound “normal” nuclei. These two distinct spectra exist due to a bifurcation in configuration space, that occurs when the nuclear repulsion (parametrized by the vector coupling constant) is increased to its nuclear matter value.     

On the configuration manifold of a liquid bridge

We show that the configuration space of an inviscid incompressible liquid bridge connecting two parallel plates has the structure of a Hilbert manifold. To construct this manifold structure we follow the general strategy of Ebin and Marsden [Groups of diffeomorphisms and the motion of an incompressible fluid, Ann. Math. 92 (1970) 102–163], where a manifold structure has been introduced for an inviscid incompressible fluid which completely fills a domain with smooth boundary.The fact that the liquid bridge has a non-smooth boundary requires extra considerations. In particular, we show how the use of Hodge theory as in the above mentioned reference can be avoided in the case of liquid bridges.     

Diffraction of a two-shock configuration by a convex cylindrical surface

The subject of this work is numerical investigation into the diffraction of a shock-wave configuration by a convex cylindrical surface. The diffraction is a stage of interaction of a shock wave with a two-dimensional body. It is preceded by the stage of shock wave reflection from the front surface of the body, the back surface of which has a convex cylindrical shape. The two-or three-shock configuration formed on the front surface diffracts by the back cylindrical surface. The emphasis is on studying the diffraction of the two-shock wave configuration with the diffraction angle varying continuously. The object under study a wedge with an inclined front surface and convex cylindrical back surface. The results of numerical investigation are obtained by integrating the Euler equations. Flow features associated with the simultaneous diffraction of the incident and reflected shock waves are revealed. The evolution of the gasdynamic system (stagnation wave + TU layer) arising inside the diffraction area is studied. Breakaway and vorticity initiation are considered. It is shown that the positions of the line of separation and TU layer change in the course of diffraction. They merge together at the stage of steady flow. Comparison is made between the flow formed upon diffraction of the two-shock configuration by the cylindrical surface and the flow generated upon diffraction by horizontal and vertical surfaces.     

Plasma confinement by a magnetic shell configuration

The confinement properties of a new magnetic shell configuration have been investigated experimentally. The diffusion coefficient D has been determined.