外光注入半导体激光器实现重复速率可调全光时钟分频

采用Fabry-Perot半导体激光器作为全光时钟分频器件,利用光注入半导体激光器产生的非线性动力学特性,实现了光脉冲的重复速率在9.0 GHz到19.8 GHz范围内连续可调的全光时钟分频. 同时利用半导体激光器速率方程,对脉冲光注入半导体激光器产生时钟分频进行了数值模拟. 实验和模拟结果表明半导体激光器在光注入的驱动下处于一周期振荡状态,当一周期振荡的二次谐波频率接近脉冲光的重复速率时,其二次谐波和基频被脉冲光同时锁定,此时将输出频率为脉冲光重复速率一半的时钟信号. 同时研究了波长失谐量和注入光功率对 关键词： 周期振荡 时钟分频 光注入 非线性动力学     

基于法布里-珀罗半导体激光器实现高重复频率光脉冲的时钟分频

实验研究了重复速率为6.32 GHz的光脉冲注人法布里-珀罗(Fabry-Perot)半导体激光器实现3.16 GHz光脉冲输出的时钟分频现象,讨论了 Fabry-Perot半导体激光器的偏置电流、注入光功率、注入光光谱以及光谱线宽等因素对时钟分频的影响.利用光注入半导体激光器产生的周期二振荡非线性动力学特性.实现了高重复速率光脉冲的时钟分频.研究表明,当注入光的光谱较窄且锁定Fabry-Perot半导体激光器某一纵模时,在较低的偏置电流和一定的注入光功率时,时钟分频才能发生.采用半导体激光器的速率方程.通过数值模拟,研究了半导体激光器的偏置电流和线宽增强因子以及注入光功率对时钟分频的影响,所得结果与实验结果相吻合.     

基于光注入Fabry-Perot半导体激光器实现同步全光分路时钟提取与波长转换

提出了一种利用Fabry-Perot（FP）半导体激光器同步提取波长转换的分路光时钟的新方法,并对该方法进行了数值模拟和实验验证.光注入半导体激光器会产生非线性单周期振荡特性,利用交叉增益调制效应及对单周期振荡的微波锁频效应,可从光时分复用信号中提取出波长转换的分路光时钟.采用一个FP半导体激光器作为全光分路时钟提取及波长转换器,数值模拟实现了从波长为1555 nm、速率为2×20 Gb/s的光时分复用信号中提取出波长转换为1550 nm、重复频率为20 GHz的分路光时钟,实验完成了从波长为155024 nm、重复频率为1236 GHz光脉冲信号中提取出相位噪声为-105 dBc/Hz的波长为154591 nm、重复频率618 GHz的分频光时钟.此外还详细研究了注入光功率、波长失谐、FP激光器偏置电流及纵模选择对光时钟提取的影响,实验结果和数值模拟结果符合.该方法在光时分复用混合波分复用通信系统中实现全光解复用及波长路由有着重要的应用价值. 关键词： 波长转换 时钟提取 光注入 非线性动力学     

光注入半导体激光器产生可调谐高频微波

利用光注入半导体激光器产生的单周期振荡,实验获得了61—129 GHz范围内频率连续可调的微波光信号.同时利用半导体激光器速率方程,对光注入半导体激光器产生高频微波进行了数值模拟.模拟和实验结果均表明微波信号产生于注入光和激光器腔模之间的拍频现象,其频率随着注入光强度和波长失谐的增大而增大,模拟结果预测该方法可以产生频率大于40 GHz的高频微波. 关键词： 光通信 光生微波 拍频 半导体激光器     

基于次谐波调制光注入半导体激光器获取窄线宽微波信号的实验研究

实验研究了处于单周期振荡的光注入半导体激光器在频率等于单周期振荡频率一半的1/2次谐波调制下所产生的微波信号的特性.实验结果显示:在合适的注入条件下,处于单周期(P1)振荡的光注入半导体激光器可输出频率可达26.5 GHz、光谱具有单边带结构的光生微波信号,但微波信号的线宽比较宽(MHz量级);通过采用频率为单周期振荡频率一半的次谐波信号调制光注入半导体激光器,可将微波线宽从十几MHz压缩到几十k Hz.进一步分析了次谐波调制信号的功率以及频率对微波信号的相位噪声的影响,并在由次谐波调制信号的功率和频率构成的参数空间绘制出了能实现次谐波频率锁定的分布区域.     

外注入非制冷式FP半导体增益开关激光器产生低抖动光脉冲的实验研究

报道了低成本、非制冷法布里-玻罗腔半导体增益开光激光器稳定地产生超短脉冲的实验研究.通过使用外部连续光注入,增益开光激光器的脉冲抖动得到了有效的抑制.实验结果表,明当选择合适功率的连续光注入到非制冷半导体增益开关激光器腔内,可以稳定地产生脉宽26 ps、抖动低于400 fs、重复频率2.5 GHz的脉冲序列.     

线宽增强因子对外光注入半导体激光器非线性单周期振荡特性的影响

线宽增强因子是影响半导体激光器输出特性的一个重要参量,不同材料不同结构类型的半导体激光器的线宽增强因子有较大的差异.利用光注入半导体激光器的单模速率方程模型,数值研究了线宽增强因子对外光注入半导体激光器的非线性单周期振荡特性的影响.结果表明:外光注入半导体激光器的动态特性对线宽增强因子的变化极为敏感,随着线宽增强因子的增加,在负失谐注入范围内单周期振荡区域显著增大,同时注入锁定的稳态输出被大大抑制.分析了线宽增强因子对非线性单周期振荡光谱特性和振荡频率的影响,结果表明:随着半导体激光器线宽增强因子的增大,单周期振荡的频率越大|当线宽增强因子不变时,单周期振荡的频率随注入光强度和频率失谐的增加而增加.     

基于单端半导体光放大器的可调谐超短光脉冲源理论与实验研究

超短光脉冲源是光时分复用(OTDM)系统中的关键器件.提出了一种基于单端半导体光放大器(SOA)的注入型主动锁模光纤激光器产生超短光脉冲的方案，建立了该方案的理论模型.实验实现了高消光比稳定的重复频率10—40GHz皮秒级光脉冲的输出，输出波长在30nm范围内连续可调. 关键词： 超短光脉冲 单端半导体光放大器 主动锁模     

光注入提高半导体激光器混沌载波发射机的带宽

外光反馈下的半导体激光器可视为混沌载波发射机.数值研究发现，外部强光注入可以显著提高混沌载波发射机的带宽，带宽提高的程度在一定范围内与注入光的强度成正比.当外部光注入系数k_inj=0.39时，混沌载波的带宽由无光注入时的2.7GHz增大到14.5GHz，提高了5倍多.研究还发现，在相同的注入强度条件下，当注入光的频率比半导体激光器的中心频率高2—4GHz时，可实现最大限度的带宽增强.此外，适当提高半导体激光器的偏置电流也可以在一定程度上提高其产生的混沌载波的带宽. 关键词： 半导体激光器 混沌 带宽     

结合光注入半导体激光器与光电环路产生频率大范围可调、窄线宽微波信号

结合光注入半导体激光器的单周期动力学态与光电环路,提出了一种可获得频率大范围可调、窄线宽的光子微波信号的方案并进行了实验研究.结果表明,光注入半导体激光器在一定条件下能够实现单周期振荡,且光子微波信号的频率在8~67GHz范围内连续可调;在合适的注入参数下,获得了频率为24.3GHz且光谱具有单边带结构的光子微波信号;通过引入光电环路结构,能够有效地将该光子微波的线宽由8.6 MHz压缩至30kHz,并获得了40dB以上的信噪比.     

Control of period-one oscillation for all-optical clock division and clock recovery by optical pulse injection driven semiconductor laser

The period-one oscillation produced by an external optical pulse injection driven semiconductor laser is applied to clock recovery and frequency division. By adjusting the repetition rate or injection power of the external injection optical pulses to lock the different harmonic frequencies of the period-one state, the clock recovery and the frequency division （the second and third frequency divisions） are achieved experimentally. In addition, in frequency locking ranges of 2 GHz and 1.9 GHz, the second and third frequency divisions are obtained with the phase noise lower than 100 dBc/Hz, respectively. Our experimental results are consistent well with the numerical simulations.     

All-optical clock frequency divider using Fabry-Perot laser diode based on the dynamical period-one oscillation

We propose and experimentally demonstrate a frequency divider implemented by an optically injected Fabry-Perot laser diode (FP-LD) based on the nonlinear dynamical period-one oscillation. Injected by optical pulses, the FP-LD will oscillate in unstable dynamical period-one (P1) oscillation. Through changing the injected strength, emitting wavelength and bias current of the FP-LD, the oscillating frequencies of the P1 state can be varied. Once one of the harmonic frequencies is adjusted to match the repetition frequency of injected optical clock pulse, the P1 oscillation will be locked, and then a divided clock at the fundamental frequency of the P1 oscillation can be generated. By utilizing this divider, we can achieve the optical clock frequency division of divide-by-two, -three and -four in a wide input frequency range, for instance, of 9.0 to 20.0 GHz for divide-by-two. The influence of injected optical power on the timing jitter of the divided clock is also investigated. It is expected that this frequency divider can be applied to high frequency division exceeding 100 GHz due to its fast P1 oscillation.     

All optical clock division and multiplication by injection mode-locked laser based on SOA

Optical clock division and multiplication were realized with an injection mode-locked fiber ring laser based on semiconductor optical amplifier SOA owing to the relatively long recovery time of carriers in SOA and the rational harmonic mode-locking. Second frequency division and 1.5th frequency multiplication of 10 GHz, second and th frequency division of 20 GHz optical pulse trains were realized, respectively, in the experiment.     

Generation of 10-GHz ultra-short pulses with low time jitter in an actively mode-locked fiber laser

We have experimentally achieved the 8.3-ps ultra-short pulse at 10 GHz repetition rate with the time jitter as low as 590 fs in an actively mode-locked fiber ring laser. The ring-cavity laser is mode-locked by a semiconductor optical amplifier based on cross-gain modulation. The external CW source is modulated with radio frequency signal by an amplitude modulator as the external optical pulses and, then, injected into the fiber ring cavity to achieve active mode locking. Further investigating the laser output characteristics, it indicates that the linewidth of employed CW source affects properties of the generated ultra-short pulse, such as phase noise and time jitter. Ultra-short pulse at high repetition rate with low time jitter can be generated by the optimization of CW laser source.     

Experimental study of a semiconductor laser diode having a Mach–Zehnder interferometer in the cavity

The performance of a semiconductor laser diode that has an asymmetric Mach–Zehnder interferometer all-optical switch in the cavity has been studied experimentally. This novel device was designed to be free from clock pulse insertion, since mode-locked optical pulses are generated internally and change the balance of the interferometer periodically. The device was fabricated using a InGaAsP/InP buried heterostructure and the primary optical properties of the device were investigated. Lasing characteristics that were peculiar to the twin-cavity structure were observed, i.e., continuous-wave lasing power oscillation in relation to the injection current balance between the two arms, and cyclic changes in the single/multiple emission peaks as a function of bias voltage at the saturable absorber. Electrical spectrum analysis indicated 40 GHz modulation of lasing output from the twin-cavity laser.