Semiconductor Fiber Research Articles

Electro-mechanical-carrier coupling model of single piezoelectric semiconductor fiber pull-out

Electro-mechanical-carrier coupling model of single piezoelectric semiconductor fiber pull-out

Comparative analysis of the impact in societies of silicon technology against that of steel

This paper will first introduce silicon and steel then deeply discuss the impact to the society. Furthermore, I will also estimate the effect to the future about these two materials. Silicon is one of the most significant and useful elements which have been used in huge amounts of fields. For instant, silicon is the primary material to make semiconductor and optical fiber even to synthesize metal-cermet, which is a core material for the spacecraft. The central processing unit (CPU) is also made by silicon, so it is a common and important element now a day. Although silicon is discovered in early 18 centuries even earlier than steel, it doesnt have a big effect in the second industrial revolution. Difference with silicon, steel is the fundamental material of cars, rail and most of the machine invented in industrial revolution because the durability and plasticity. However, this valuable material cant be efficiently produced until Bessemer converter comes out. This machine developed the first process for manufacturing steel inexpensively.

Principle and application of amplifier of fiber on fiber communication

As the most widely used and the most reliable way of communication in the world today, the development of optical fiber communication will inevitably affect the world. As an important component of fiber communication system, the development of fiber amplifier directly affects the development of fiber communication. The fiber amplifier is divided into semiconductor fiber amplifier, mixed with rare earth element fiber amplifier and nonlinear fiber amplifier. This paper aims to study the principle, function and equipment of the fiber optic amplifier. Some limitations and prospects for the future are also proposed.The principle, function and limitation of erbium-doped fiber amplifier are emphasized. It is a summary of the development of fiber amplifier in recent years, and it is convenient for other scholars to find and study the data of fiber amplifier. This paper summarizes the development of fiber amplifier in recent years, and explains the basic principles of fiber amplifier, so that other scholars to find the data of fiber amplifier, convenient for other scholars to study.

Forward-stimulated Brillouin scattering in silicon-core fibers

As a new type of semiconductor fiber, silicon-core fibers have a higher non-linear effect compared with silica fibers. Forward-stimulated Brillouin scattering as a typical optical non-linear effect holds strong promise for applications in, for example, fiber-optic sensing. The study of the FSBS effect in silicon-core fibers facilitates further theoretical exploitation of the potential of FSBS in fiber-optic sensing. In this paper, the FSBS in the silicon-core fiber is studied using the finite element method. The model is based on a silicon-core fiber, whose silicon-core diameter is 4 μm and silica cladding diameter is 33.4 μm, and the optical field modes are classified by the vector method to obtain the acoustic field modes excited by FSBS—radial mode (R0m) and torsional radial mode (TR2m). The FSBS gain of the fiber shows that R0m has the best coupling with TM and TE optical modes, and TR2m has the best coupling with HE optical modes. It is concluded that the sound field frequency shift of R0m is more sensitive to the change in the effective refractive index of the optical field than that of TR2m. The factors affecting the gain are refined into photoelastic effects and moving boundary perturbations, and their contributions to the total gain are summarized. Finally, it was confirmed that a strong FSBS gain similar to 365.57 (1/mw) can be obtained with silicon-core fibers without the need to reduce the size to the usual dimensions of silicon waveguides, paving the way for further research studies in areas such as frequency-tunable laser emission, mode-locked pulsed lasers, low-noise oscillators, and optical gyroscopes.

Nonlinear finite element analysis of electromechanical behaviors in a piezoelectric semiconductor beam

In this paper, a one-dimensional beam model with extensional, flexure and shearing deformations for a piezoelectric semiconductor fiber is established based on the first-order beam theory and nonlinear electric current constitutive relation. To solve such a nonlinear beam model under transverse and axial forces, a finite element method is proposed together with an iterative process. Throughout numerical case studies, effects of the external forces and initial electron concentration are investigated on electromechanical fields. It is shown that the applied forces have a great influence on the distribution of electron concentration, which can freely regulate the electron transport in piezoelectric semiconductors.

Systematic error analysis and parameter design of a vision-based phase estimation method for ultra-precision positioning.

Ultra-precision position measurement is increasingly important in advanced manufacturing such as the semiconductor industry and fiber optics or photonics. A vision-based phase estimation method we proposed previously performs position measurement by imaging a 2D periodic pattern. In this paper, systematic errors of this method are analyzed and derived mathematically, which are classified into two types: spectrum leakage error caused by image truncation and window function modulation, and sub-pixel error resulting from discrete Fourier transform (DFT) intensity interpolation. Key design parameters are concluded including pattern period T, camera pixel size t and resolution N, as well as the type of window function used. Numerical simulations are conducted to investigate the relationship between the phase errors and design parameters. Then an error reduction method is proposed. Finally, the improved performance of parameter optimization is validated by a comparative experiment. Experimental results show the measurement errors of the prototype are within ∼2 nm in X or Y axis, and ∼1µrad in axis, which reaches the sub-pixel accuracy better than 10-3pixel.

A convenient approach to tuning the local piezopotential of an extensional piezoelectric semiconductor fiber via composite structure design

It has been demonstrated that the local piezopotential property of a piezoelectric semiconductor (PS) fiber has a great influence on its piezotronic performance. However, tuning the local piezopotential of the PS fiber is quite difficult due to its small size. To solve this problem, a feasible approach, i.e., composite structure design, is proposed in this paper. A two-layer composite structure is utilized to demonstrate that the local piezopotential of a PS fiber can be tuned by axial forces applied at the two ends. Based on the one-dimensional phenomenological model, theoretical and numerical analysis are performed and the local manipulation mechanism is successfully illustrated. It shows that local potential barriers and wells will emerge as long as the piezoelectric polarization is discontinuous along the fiber. The properties of these barriers and wells, including the number, the relative heights and depths, directly depend on the material combination and geometry size of different composite components, which makes it possible to artificially design the piezotronic performance of PS fibers. It also shows that the output voltage of a PS fiber based nanogenerator is significantly improved when employing composite structures. This is because part of electrons are confined to the produced local barrier, thus reducing the number of electrons that would screen the piezopotential near the two ends. In addition, the I-V characteristic of the composite fiber is further studied and its dependence on the local potential change is revealed. Conclusions obtained in the present paper have great potential applications in piezotronic field.

Picosecond hybrid laser based on semiconductor laser, fibre and Nd: YVO4 amplifiers. Investigation of effects limiting the peak power

Based on a distributed-feedback (DFB) semiconductor laser, an ytterbium fibre amplifier, an Nd : YVO4 amplifier, and a frequency converter, we designed a hybrid picosecond laser for satellite laser ranging. A gain exceeding 108 is achieved while maintaining the temporal shape and spectrum of the pulses, with a low noise level and a divergence close to the diffraction limit. The pulse energy after conversion to the second harmonic at λ = 532 nm is 2.2 mJ with a duration of 27 ps and a repetition rate of 1 kHz. It is shown that the main effects limiting the peak power are spectrum broadening due to self-phase modulation in a fibre amplifier and large-scale self-focusing in the Nd : YVO4 amplifier. Optimisation of the amplifier geometry and the use of a uniform profile of the pump radiation intensity make it possible to reduce the effect of self-focusing and increase the energy efficiency of the amplifier.

Design and Heating Simulation of Continuous Laser Welding Curing Device for Carbon Fiber Composite Repair

Rapid repair of composite materials is a major challenge in composite applications. At present, the mainstream method is to use the heat repair instrument and the prefabricated patch bonding, but there are some problems, such as slow heating, uncontrolled temperature gradient and long curing time. Laser curing is a new type of carbon fiber composite material with fast curing time and good curing effect. The laser heating technology curing equipment designed in this paper consists of laser heating device, mobile device, rotating device, etc. The specific curing method is to use semiconductor fiber laser to cure the composite material when the laser and carbon fiber material are moving. Simulation software of laser heating process is simulated, and the resin base carbon fiber composite material as the research object, established three-dimensional physical model of laser heating carbon fiber composite materials, simulation and calculate the temperature field distribution in the laser heating process of carbon fiber composite materials and rule, a preliminary analysis of the laser parameters on the influence law of temperature of carbon fiber composite materials. As the laser power of the heating device laser increases, the average temperature and the maximum temperature achieved by the carbon fiber composite will be increased. With the acceleration of the laser moving speed of heating equipment, the maximum temperature that carbon fiber composite material can achieve will decrease, but the average temperature will rise in a certain range, which can have a certain insulation effect. The research results can provide certain reference for the temperature field simulation in the process of laser carbon fiber composite material.

Typical transient effects in a piezoelectric semiconductor nanofiber under a suddenly applied axial time-dependent force

Based on the mechanical motion equation, Gauss’s law, and the current continuity condition, we study a few typical transient effects in a piezoelectric semiconductor (PS) fiber to realize the startup and turning-off functions of common piezotronic devices. In this study, the transient extensional vibration induced by a suddenly applied axial time-dependent force is examined in a cantilevered n-type ZnO nanofiber. Neither the magnitude of the loadings nor the doping concentration significantly affects the propagation caused by disturbance of the axial displacement. However, both of the factors play an important role in the propagation caused by disturbance of the electron concentrations. This indicates that the electromechanical coupling effect can be expected to directly determine the electronic performance of the devices. In addition, the assumption of previous simplified models which neglect the charge carriers in Gauss’s law is discussed, showing that this assumption has a little influence on the startup state when the doping concentration is smaller than 1021 m−3. This suggests that the screening effect of the carriers on the polarized electric field is much reduced in this situation, and that the state is gradually transforming into a pure piezoelectric state. Nevertheless, the carriers can provide a damping effect, which means that the previous simplified models do not sufficiently describe the turning-off state. The numerical results show that the present study has referential value with respect to the design of newly multifunctional PS devices.

Application of the homopoty analysis method to nonlinear characteristics of a piezoelectric semiconductor fiber

Application of the homopoty analysis method to nonlinear characteristics of a piezoelectric semiconductor fiber

Mid-infrared supercontinuum generation of 1.14 W in a fluoroindate fiber pumped by a fast gain-switched and mode-locked thulium-doped fiber laser system

We report the generation of a spectrally flat supercontinuum in a fluoroindate ( I n F 3 ) fiber with a maximum time-averaged output power of 1.14 W and a spectrum extended to 4.75 µm. The pump source was a fast gain-switched and semiconductor saturable absorber mirror mode-locked thulium Tm-doped fiber laser followed by a cascade of two Tm-doped fiber amplifiers. The repetition rates of the gain-switched pulses and mode-locked sub-pulses were 50 kHz and 111 MHz, respectively, whereas the duration of sub-pulses recorded within a gain-switched pulse envelope was ∼ 110 p s . This home-built pump laser system provided an output average power of 2.45 W at a central wavelength of 2 µm. To the best of our knowledge, this is the first paper on supercontinuum generation in an I n F 3 fiber pumped by a fast gain-switched and mode-locked laser system. This approach is promising for further efficient continuum generation in the mid-infrared region.

Analysis of Stainless Steel Waste Products Generated during Laser Cutting in Nitrogen Atmosphere

Laser cutting technology is one of the basic approaches used for thermal processing of parts fabricated from almost all engineering materials. Various types of lasers are utilized in the industry with different attendant gases such as nitrogen or argon. When the laser beam interacts with a metal surface, the area underneath is heated to the melting point. This liquid or vaporized metal is ejected from the kerf area to the surrounding atmosphere by attendant gas and becomes undesirable waste in the form of powder. In the presented work, the X-ray diffraction, scanning electron microscopy, electron backscatter diffraction, transmission electron microscopy, and energy-dispersive X-ray spectroscopy methods were used to analyze AISI 304 stainless steel, which was cut by a semiconductor fiber laser, and the waste powder generated during the laser cutting process. The results suggest that this waste material may be reused for industrial applications such as additive manufacturing.

Transient Bending Vibration of a Piezoelectric Semiconductor Nanofiber under a Harmonic Shear Force

A harmonic shear end force induced the transient bending vibration is analyzed in a cantilevered n-type ZnO nanofiber. Based on the mechanical movement equation, continuity condition of current density and charge equation of electrostatics, the theoretical analysis is carried out by a one-dimensional model. The evolution of the deflection and perturbation of the electron concentration caused by the harmonic end force are calculated. Numerical results show that the vibration period of the piezoelectric semiconductor fiber is about twice that of the harmonic force, which referenced to design the nanosensors and nanogenerators.

A Continuously Tunable Booster Optical Amplifier-Based Fiber Ring Laser Covering L and Extended L Bands

ABSTRACT We propose and demonstrate a simple design of semiconductor fiber ring laser covering a broad tunable range, comprising L and extended L bands. The proposed laser can be continuously tuned over 54 nm from 1578 to 1632 nm with a total output power of around 5.2 dBm and having a side mode suppression ratio (SMSR) of around 55 dB by incorporating a Fabry Pérot tunable filter. The generated output is highly stable with power and wavelength fluctuations within 0.2 dB and 0.05 nm, respectively.

Electrical Response of a Multiferroic Composite Semiconductor Fiber Under a Local Magnetic Field

We study the electrical response of a multiferroic composite semiconductor fiber consisting of a piezoelectric semiconductor layer and two piezomagnetic layers under a transverse magnetic field applied locally to a finite part of the fiber. The phenomenological theory of piezomagnetic-piezoelectric semiconductors is employed. A one-dimensional model is derived for magnetically induced extension of the fiber. For open-circuit boundary conditions at the two ends of the fiber, an analytical solution is obtained from the model linearized for small carrier perturbations. The solution shows a local electric polarization and a pair of local electric potential barrier-well. When the two ends of the fiber are under a voltage, a nonlinear numerical solution shows that the potential barrier and well forbid the passage of currents when the voltage is low. The results have potential applications in piezotronic devices when magnetic fields are involved for manipulating the devices or sensing and transduction.

Magnetically Controllable Piezotronic Responses in a Composite Semiconductor Fiber with Multiferroic Coupling Effects

Magnetically Controllable Piezotronic Responses in a Composite Semiconductor Fiber with Multiferroic Coupling Effects

Magnetically Controllable Piezotronic Responses in a Composite Semiconductor Fiber with Multiferroic Coupling Effects

Herein, a multiferroic composite semiconductor (MCS) fiber, in which the carriers transport behaviors can be effectively controlled by applying a magnetic field, is proposed. The fiber consists of two outer piezomagnetic (PM) layers, two piezoelectric (PE) layers, and a semiconducting core, and hence exhibits the comprehensive magneto–electro–semiconductive (MES) coupling effects. Based on the basic equations of multiferroic composites and the drift‐diffusion model of currents in semiconductor physics, a 1D theoretical model for the laminated MCS fiber with the MES coupling effects is presented, and an analysis of the extensional deformation induced by a magnetic field is conducted. The electrons move toward one end of the fiber under the PE field resulting from the MES coupling mechanism. As a result, this leads to the redistribution of electrons in the fiber. Theoretical results show that the magnetic field as well as the initial concentration of carriers and the volume fraction of the PM or PE layer have obvious effects on the carriers transport properties and mechanical behaviors of the MCS fiber. Compared with the mechanical tuning method of piezotronics, such a magnetic field based tuning method via the MES coupling effects has some advantages because it is remote and contactless.

I-V characteristics of a piezoelectric semiconductor nanofiber under local tensile/compressive stress

We study the electrical behavior of a piezoelectric semiconductor fiber under local extensional or compressive stress and an applied voltage. A numerical analysis based on a one-dimensional phenomenological model is performed. The current-voltage relation is obtained. It is found that when the applied voltage is below a stress-dependent critical value, no current can flow through the fiber in either direction. When the voltage is above the critical voltage, currents can flow in one direction but not the other. When the voltage is above a second critical value, currents can flow in both directions. Thus, the local stress acts like a switch, which can turn the currents on and off in one or both directions. This provides a basic means for mechanically manipulating the electrical behavior of piezoelectric semiconductor fibers and thus serves as a fundamental element of piezotronics.

Electrical behaviors of a piezoelectric semiconductor fiber under a local temperature change

We study the effects of a local temperature change on the electrical behaviors of a piezoelectric semiconductor fiber in extensional deformation. A one-dimensional model for thin fibers derived previously from the macroscopic theory of thermopiezoelectric semiconductors is used. Through a combined theoretical and numerical analysis, it is shown that a local temperature change produces a local electric potential barrier and a potential well, which prohibits the flow of currents along the fiber unless the voltage is above a temperature-dependent critical value. The results are useful for thermally manipulating the currents in the fiber and have potential applications in piezotronics.