Tao Shang

Xidian University

The influence of barrier thickness fluctuation scattering (BTFS) on the transport properties of the two-dimensional electron gas (2DEG) in undoped MgZnO/ZnO heterostructures (HSs) has been studied theoretically. The electronic states of the MgZnO/ZnO quantum well (QW) are obtained by solving the Schrödinger and Poisson equations self-consistently....

The performances of the decode-and-forward (DF) multihop free-space optical communication system with exponentiated Weibull distribution considering the fading induced by pointing error have been studied. With Meijer's G-function, the probability density function (PDF) of the aggregated channel model and the closed-form expression for the average b...

Based on the Kundu–Eckhaus equation with variable coefficients, the exact one-soliton and two-soliton solutions have been explicitly given by an appropriate similarity transformation method. As an example, an exponential distributed fiber control system, nonlinearity management system and disper-sion management system have been considered, and the...

The average bit error rate (BER) for binary phase-shift keying (BPSK) modulation in free-space optical (FSO) links over turbulence atmosphere modeled by the exponentiated Weibull (EW) distribution is investigated in detail. The effects of aperture averaging on the average BERs for BPSK modulation under weak-to-strong turbulence conditions are studi...

In this paper, a novel amplitude-phase modulation format, inverse-return-to-zero minimum shift keying (IRZ-MSK), is proposed. A scheme to realize the IRZ-MSK is introduced, and especially a method of demodulating the phase branch is presented. The influence of different duty cycles on the performance of the IRZ-MSK is discussed. Numerical simulatio...

Considering the ultrashort optical soliton propagation in the non-Kerr media, the cubic-quintic nonlinear Schrödinger equation with Raman effect is studied through the depen- dent variable transformation and Hirota method. Based on symbolic computation, the bilinear form, the explicit one- and two-soliton solutions for the equation are presented...

The evanescently coupled multicore waveguide lattice composed of 37 linear type I cores hexagonally arranged has been theoretically studied and fabricated by low-repetition-rate femtosecond laser inscription of bulk fused silica. The effects of the single core's numerical apertures (NAs) and spacing on the mode characteristics of the 37-core wavegu...

In order to ensure the communication link stability in mobile FSO system, a new omni-directional optical antenna is designed. Being aimed at discontinuous tracking, a novel beam control method based on the error correction Kalman prediction algorithm (EC-KPA) is proposed. The comparison of EC-KPA and the conventional Kalman prediction algorithm (KP...

In this paper, an all-optical orthogonal frequency division multiplexing (OOFDM) system based on the multi-amplitude minimum shift keying (MAMSK) modulation is proposed. A scheme to realize MAMSK is designed, and the influence of modulation index on the performance of MAMSK is discussed. Numerical simulations and analysis are performed, and the com...

Due to the notable influence of atmospheric effects and the objects relative motion, acquisition, pointing and tracking (APT) are the key technologies to establish the communication link in free space optical communication (FSO). In this paper, an all-direction, cylinder-shaped optical antenna is proposed, and the theory and method of beam control...

In order to ensure the communication link stability in mobile free-space optical communication (FSO) system, a novel omni-directional regular icosahedron-shaped optical antenna is designed and its beam control method is proposed. The beam control strategy is studied in detail, which includes the switch between the transmission units on the same tra...

A novel integrated Mach-Zehnder modulator consisting of three phase modulators to generate an optical single sideband with carrier signals in the radio-over-fiber system has been proposed. By adjusting the direct current voltage applied in the modulation arm, named the “direct current arm,” the power of the optical carrier in the optical single sid...

Atmospheric turbulence induced fading is one of the main impairments affecting the operation of free-space optical (FSO) communication systems. In this paper, the average bit error rate (BER) of M-ary pulse position modulation (PPM) is analyzed under Gamma-Gamma fading channel. Using the characteristics of Meijer G function, Closed-form expression...

In this paper, we have proposed a novel approach to generate optical carrier suppression (OCS) mm-wave with signal only carried by one first-order sideband using a dual-parallel MZM in radio-over-fiber (RoF) system, and the transmission performance was also investigated. As the optical mm-wave signal is transmitted along the fiber, there is no time...

We have proposed and demonstrated a novel Mach–Zehnder modulation technique which employs a 1×4 multimode interference MMI coupler and four optical phase-modulator waveguides to generate optical single sideband (SSB) signals in radio-over-fiber (ROF) transmission link. It is shown that when the RF (radio frequency) modulation index is large, the op...

The influence of extinction ratio (ER) on the performance of 120 Gbps return-to-zero octal differential phase-amplitude-shift keying (RZ-ODPASK) modulation format in single-channel transmission is investigated. Based on the modulation and demodulation schemes, the structures of RZ-ODPASK transmitter and receiver are presented; and expressions for t...

The differential precoder is a key component for high-speed optical differential quadrature phase-shift keying (DQPSK) transmissions, and a method of the implementation of differential precoder for high-speed optical DQPSK modulation is introduced in this paper. This method first researches the optical DQPSK encoder and decoder, and then gets the f...

This paper presents a numerical analysis and comparison on the performance of multi-pump gain-flat Raman amplifiers based on triangular photonic crystal fiber and conventional fiber. It is demonstrated that the extra 5.93 dB Raman net gain can be achieved in the L-band when PCF acts as Raman gain medium. The noise performance of the two amplifiers...

A numerical design on the triangular photonic crystal fiber (PCF) based backward multi-pump Raman amplifier is presented. It is demonstrated that high flat Raman gain can be reached based on PCF. Influences of different geometric parameters and germanium doping concentrations on the Raman net gain, amplified spontaneous emission (ASE) noise and dou...

Due to triangular photonic crystal fiber (PCF) high nonlinearity and low dispersion slope, using the condition that the different linear phase shift combination must satisfy the phase match, the expressions of gain and bandwidth for one-pump fiber-optic parametric amplifiers (1P-FOPA) based on PCF in the normal and abnormal dispersion regimes are d...

In this paper, ASE (amplified spontaneous emission) noise induced by parametric gain and spontaneous Raman scattering in optical fiber Raman amplifier is analyzed. Expressions regarding the generation and amplification of such kind of noise are present. Simulations are carried out on a forward WDM pumping fiber Raman amplifier and a long haul trans...

In this paper, amplified double Rayleigh backscattering noise (DRB) in the optical fibre Raman amplifier is analysed. Expressions are presented for both forward pumping and backward pumping schemes. Calculation is performed to show the effective suppression of DRB noise by employing an optical isolator. The optimal position for the isolator is dete...

In long haul wavelength division multiplexing (WDM) optical transmission systems, fiber Raman amplifier will become an important subsystem because of its unique advantages. This paper is concentrated on one kind of noise in fiber Raman amplifiers - amplified spontaneous emission (ASE) noise induced by parametric gain (PG). When a strong optical wav...

An optical packet switching architecture employing multiple groups of partially shared buffering is proposed and its performance on packet contention resolution is analyzed. Simulation results are present and comparison of packet loss probability between single group of partially shared buffering and multiple groups of partially shared buffering of...

In this paper, we propose an optical switch that combines both shared tunable wavelength converter and partially shared buffering together. The packet contention can be resolved both in the time domain (output buffering and partially shared buffering) and frequency domain (wavelength conversion) simultaneously and switching performance can be great...