垂直腔半导体光放大器的增益特性数值分析

结合垂直腔半导体光放大器(VCSOAs) 的竖直微型腔结构带来的特性,在反射工作模 式情况下,分析了VCSOAs 的增益特性。通过数值求解激光器单模速率方程,给出了增益、饱和输出功率随泵浦光功率、出射腔面反射率的变化,分析了其功率动态范围。得出了提高腔面反射率能使增益得到增长,以及强泵浦光功率能起到平坦增益,增大增益的作用的结论。总结了VCSOAs 设计中的一些规律,以作实际应用中参考。     

垂直腔半导体光放大器增益的理论分析

针对研究增益饱和时,现有的垂直腔半导体光放大器(VCSOA)速率方程模型在确定输入信号的功率注入因子方面存在难题,根据法布里-珀罗腔边界条件,从行波方程和与位置相关的载流子方程出发,引入随轴向位置发生变化的增益增长因子刻画微腔内的驻波效应,构建出VCSOA的增益模型。利用该模型通过求方程的自洽得到了腔内载流子、光子的分布,并分析了反射增益,其结果与已报道的理论及实验基本一致。     

垂直腔半导体光放大器频率响应特性研究

从速率方程出发,利用小信号分析方法对垂直腔半导体光放大器(VCSOA)的频率响应特性进行了研究.在考虑了量子阱材料中的增益和载流子浓度之间的对数关系后,得到了VCSOA的峰值响应频率以及3 dB频率响应带宽的解析表达式.结果表明,VCSOA的频率响应特性受抽运光强度、输入光功率以及自发辐射因子的影响.     

具有宽带调制特性的SOA的优化设计考虑

基于半导体光放大器（ＳＯＡ）的高频滤波效应，分析了半导体光放大器的偏置电流，微分增益，输入光功率和模场限制因子与半导体光放大器响应速度（载流子密度响应速度）关系，给出了具有高速响应特性的半导体光放大器各参量的优化设计方法。     

垂直腔半导体光放大器调谐输出特性分析

为了分析垂直腔半导体光放大器的调谐输出特性,考虑到有源腔有效折射率和载流子浓度之间的关系,并结合载流子速率方程,采用建立腔内平均光子数与输入信号光功率之间的关系的研究方法,对垂直腔半导体光放大器的调谐输出特性进行了理论分析和数值仿真.结果表明,在一定的输入光功率和波长条件下,可以观察到双稳现象;双稳环的宽度随着输入光功...     

半导体光放大器增益饱和及其开关特性的研究

从理论上研究了行波半导体光放大器的增益饱和特性。由半导体的单模速率方程出发，应用半导体光放大器的传输波动方程，推导了放大器的增益特性表达式。根据半导体光放大器增益饱和特性，研究了开关特性。     

锥形有源条半导体光放大器增益和饱和特性分析

以行波半导体光放大器速度方程为基础，采用传输矩阵方法，对锥形结构半导体光放大器的增益和饱和特性进行理论研究。讨论了不同锥形长度，不同结构时的增益和饱和特性差异。理论研究表明，锥形结构能改善半导体光放大器的偏振灵敏度。在同一锥度下，长锥形长度能提高饱和增益，降低偏振度。在进行半导体光放大器有源条结构设计时要综合考虑锥度及锥形长度的影响，以实现结构优化 。     

行波半导体光放大器的增益饱和及其在解复用技术中的应用

本文通过对行波半导体光放大器增益饱和及其瞬态增益特性的分析，指出了利用半导体光放大器增益饱和快的特点，可使半导体光放大器环路镜实现超高速的解复用功能。     

波分复用-光时分复用波长转换信号的消光比研究

对基于半导体光放大器(SOA)交叉增益调制(XGM)效应的全光波分复用一光时分复用(WDM—OTDM)转换后的两路时分复用输出信号的消光比(ER)特性进行了分析。研究了两路波分复用的输入抽运光和探测光的功率、波长、抽运光的消光比、数据速率以及半导体光放大器的偏置电流、腔长和模场限制因子对转换信号消光比的影响。模拟结果表明，增大抽运光输入功率，选择长波长抽运光，可以增加转换光相应信道消光比，但减小了相邻信道的输出消光比；增加抽运光消光比，可以提高转换光消光比，但各个信道增长幅度不同；减小探测光输入功率，选取短波长探测光波长，增加半导体光放大器的腔长和模场限制因子以及大的偏置电流可提高转换光消光比；对于两路或多路波分复用信号转换时分复用信号的过程中，一定要考虑转换光每个信道消光比的均衡。     

半导体光放大器的增益特性和偏振特性

介绍了半导体光放大器的两个重要特性:增益特性和偏振特性。增益特性中,描述了放大器中增益调制现象和增益饱和现象,并介绍了提高半导体光放大器增益的方法。偏振特性中,分析了半导体光放大器增益偏振敏感产生的原因,并列举了低偏振敏感度放大器的实现方法。最后报道了近几年才被注意的半导体光放大器相位偏振敏感特性。     

Design and analysis of vertical-cavity semiconductor opticalamplifiers

The authors present detailed, yet largely analytical, models for gain, optical bandwidth, and saturation power of vertical-cavity semiconductor optical amplifiers (VCSOAs) in reflection and transmission mode. Simple formulas for the gain-bandwidth product are derived. The saturation model considers a sublinear material gain, gain enhancement by the standing-wave effect, and all relevant carrier recombination mechanisms. Excellent agreement with measurements on novel 1.3-μm VCSOAs is obtained. The models are used to analyze device performance and to investigate optimization options. Parameter plots are given which allow for an easy exploration of the VCSOA design space, matching desired performance data with the required mirror reflectivity and pump current     

垂直腔半导体光放大器带宽特性研究

为了研究垂直腔半导体光放大器(vertical cavity semiconductor optical amplifiers,VCSOA)中抽运光功率、分布布喇格反射镜(distributed Bragger reflector,DBR)周期数以及输入信号强度对其带宽特性的影响,采用传输矩阵法进行了数值模拟。计算模型中考虑了载流子和光强沿纵向的分布,以及腔内介质折射率的不均匀性对光波传输的影响。得到的结果与文献中的结论符合较好。结果表明,提高VCSOAs的抽运水平可以增大其峰值增益,同时会缩小其增益带宽;减小DBR周期数可以获得更大的增益带宽积。另外,输入光信号强度对VCSOA带宽的大小也有较大的影响。     

MEMS-tunable vertical-cavity SOAs

We present the signal gain, wavelength tuning characteristics, saturation properties, and noise figure (NF) of MEMS-based widely tunable vertical-cavity semiconductor optical amplifiers (VCSOAs) for various optical cavity designs, and we compare the theoretical results to data generated from a number of experimental devices. Using general Fabry-Pe/spl acute/rot relationships, it is possible to model both the wavelength tuning characteristics and the peak signal gain of tunable vertical-cavity amplifiers, while a rate-equation analysis is used to describe the saturation output power and NF as a function of the VCSOA resonant wavelength. Additionally, the basic design principles for an integrated electrostatic actuator are outlined. It is found that MEMS-tunable VCSOAs follow many of the same design trends as fixed-wavelength devices. However, with tunable devices, the effects of varying mirror reflectance and varying single-pass gain associated with the MEMS-based tuning mechanism lead to changing amplifier properties over the wavelength span of the device.     

Optical level equalisation based on gain saturation in fibreoptical parametric amplifier

Optical level equalisation operation based on gain saturation in an optical fibre parametric amplifier is reported. The signal output has been measured as a function of the signal input in a fibre parametric amplifier, with the result that the signal gain saturates as the input power increases and the output power reached a maximum value at a particular input level. Utilising this gain saturation property, optical level equalisation has been demonstrated     

Long wavelength vertical-cavity semiconductor optical amplifiers

This paper overviews the properties and possible applications of long wavelength vertical-cavity semiconductor optical amplifiers (VCSOAs). A VCSOA operating in the 1.3-μm wavelength region is presented. The device was fabricated using wafer bonding; it was optically pumped and operated in reflection mode. The reflectivity of the VCSOA top mirror was varied in the characterization of the device. Results are presented for 13 and 12 top mirror periods. By reducing the top mirror reflectivity, the amplifier gain, optical bandwidth, and saturation output power were simultaneously improved. For the case of 12 top mirror periods, rye demonstrate 13-dB fiber-to-fiber gain, 0.6 nm (100 GHz) optical bandwidth, a saturation output power of -3.5 dBm and a noise figure of 8.3 dB. The switching properties of the VCSOA are also briefly investigated. By modulating the pump laser, we have obtained a 46-dB extinction ratio in the output power, with the maximum output power corresponding to 7-dB fiber-to-fiber gain. All results are for continuous wave operation at room temperature     

Vertical cavity semiconductor optical amplifiers: comparison ofFabry-Perot and rate equation approaches

Accurate calculation of gain saturation properties of vertical-cavity semiconductor optical amplifiers (VCSOAs) relies on correct calculation of the average photon density in the amplifier. The most popular methods to study optical amplifiers are based on Fabry-Perot and rate equation approaches. However, they are known to give significantly different results. This paper shows that using the general Poynting theorem, it is possible to reconciliate the two methods by reconsidering the calculation of the mirror losses in the rate equation approach     

Limits on amplification of picosecond pulses by using semiconductorlaser traveling-wave amplifiers

The limiting factors in picosecond pulse amplification by semiconductor traveling-wave laser amplifiers are investigated, including the effects of the spontaneous emission. For the amplifier with a negligible amount of spontaneous emission, amplification is limited by the energy saturation for low-repetition-rate pulses, while the power saturation is the limiting factor for high-repetition-rate pulses. The spontaneous emission decreases both the signal gain of the amplifier and the signal-to-noise ratio considerably. The effective gain recovery time and the effective saturation energy are strong functions of the input pulse energy, and the amount of the spontaneous emission     

Amplified spontaneous emission and gain characteristics ofFabry-Perot and traveling wave type semiconductor laser amplifiers

Semiconductor laser amplifiers are investigated with respect to amplified spontaneous emission power and gain characteristics. The influence of the spontaneous emission coefficient, input power, and facet reflectivity on amplifier saturation characteristics is analyzed. It is shown that a small β, zero reflectance device has advantageous properties in terms of high gain and output power at the 3-dB compression point. The low reflectance contributes to a slow saturation, whereas a low β means a larger optical model and hence lower intensities and less saturation for a given output power or gain