基于光注入半导体激光器的超宽带信号产生

UWB signals generation based on an optically injected semiconductor laser

摘要:

提出一种基于光脉冲注入条件下半导体激光器腔 内交叉增益调制(XGM)效应的超宽带(UWB)信号产生方案,通过一个增益开关激光器(ML)、 一个半导体激光器(SL)和一个光带通滤波器(OBPF),在平衡探 测器(BPD)端口直接检测输出重复频率为2.5GHz的UWB一阶微分(Mo nocycle)和二阶微分(Doublet)信号, 而且通过引入马赫-曾德尔调制器(MZM),还可对产生的UWB信号实现开关键控(OOK)。 对所提系统 进行了全面的系统仿真分析,并进行了实验验证,实现了上述各种条件的UWB信号产生,并 实现了UWB信 号的40km光纤传输实验。实验结果表明:该方案获得的UWB信号的频 谱与美国联邦通信委员会(FCC)定制的EIRP标准吻合,同时经过调制的 UWB信号的波形经40km光纤传输之后基本保持不变。为了证明本文方 法产生的UWB信号的重复变化特点,还产生了频率为3.75GHz的UWB信 号。

Abstract:

A novel scheme to generate high-speed ultra-wideband (UWB) signals based on a semiconductor laser under optical pulses injection is proposed.This study presents the generation of the UWB monocycle and doublet signals with a repetition of 2.5GHz and investigates the on-off ke ying (OOK) modulation of the generated UWB signals through a Mach-Zehnder modulator (MZM).Using the combina tion of a gain-switched laser (GSL) as the master laser (ML) and a semiconductor laser wi thout isolator as the slave laser (SL),the generated of monocycle UWB signals or doublet UWB signals are directly detected by a balanced photodiode (BPD) after the optical spectrum output from the ML eliminated by an optical bandpass filter (OBPF).Comprehensive and systematic ana lysis is also given and experimentally demonstrated,realizing the 40km transmi ssion.The experimental results demonstrate that the spectra of the acquired UWB signals match well with those of the standard UWB signals and the FCC mask,and moreover,the waveforms of the UW B signals are well maintained after transmission.To demonstrate the repetition variation of t he generated UWB signals by using this scheme,the generation of 3.75GHz UWB signals is also demo nstrated.