基于PPMgLN晶体的全光通信波长转换器研究

摘要

波长变换技术是组成全光分组交换网中的重要技术之一,而当前比较成熟的基于半导体光放大器的波长转换技术在传输速率、信号格式、波长转换通道数和灵活性上还存在缺陷,不利于今后高速大容量光网络的发展。本文提出了基于周期极化掺氧化镁铌酸锂（PPMgLN）晶体的非线性波长转换方案,该方案采用I型准相位匹配（QPM）技术实现宽带倍频（SHG）、和频（SFG）和差频（DFG）,再通过级联二阶倍频差频（cSHG/DFG）或级联二阶和频差频（cSFG/DFG）波长转换机制,实现全光通信波长转换。在全光网络中,该方案能够很好地解决波长竞争、传输格式达到完全透明、降低网络阻塞率、提高网络传输速率等问题。%The technology of wavelength conversion is the one of most important technology in all optical wavelength division multiplexing communication networks. Currently, the matured wavelength conversion based on semiconductor optical amplifier has some defects, such as transmission rate is not fast, not strictly transparent to signal format, wavelength conversion channels is not enough and the flexibility of optical networks is not good. Those defects limit the development of high-speed and large-capacity optical networks in future. A new method of nonlinear wavelength conversion based on PPMgLN crystal is given in this paper. This method adopt the technology of type I quasi phase matched(QPM) to realize broadband second harmonic generation(SHG) effect, sum frequency generation(SFG) effect and difference frequency generation(DFG) effect. Afterwards, utilizing the wavelength conversion mechanism of cascaded SHG/DFG and cascaded SFG/DFG to realize all optical wavelength conversion. In optical networks, this method can resolve the problem of wavelength competition, strictly transparent to signal format, the optical networks blocking rate and the optical networks transmission rate.