全光无滤波可调可切换超宽带脉冲产生的研究

项目名称： 全光无滤波可调可切换超宽带脉冲产生的研究

项目编号： No.61501088

项目类型： 青年科学基金项目

立项/批准年度： 2016

项目学科： 无线电电子学、电信技术

项目作者： 胡哲峰

作者单位： 电子科技大学

项目金额： 21万元

中文摘要： 无线通信中的超宽带（UWB）技术由于具有带宽极宽、传输速率较高、发射功率很低且功耗小、保密性较好等优点，因而在短距离、大容量无线通信系统及宽带传感网络中具有非常大的应用潜力。但由于UWB信号不适宜在空气中长距离传输，而光纤系统在长距离传输时则具有低损耗、抗干扰能力强等特点，因而在光域内直接产生UWB信号近来引起了极大的关注。目前已报道的很多方案需要使用特别设计的滤波器，增加了系统的成本。另外可调又可切换的方案非常少，且产生的信号不在单一波长上。本项目拟使用双端面入射的半导体光放大器中的非线性效应来得到极性互为相反的同一波长的高斯脉冲，然后在脉冲间引入可调延时，通过组合方式的选择以及延时量和光功率的调节来实现UWB脉宽和射频谱的可调谐，以及脉冲极性的可切换。这样就极大地简化了系统结构，降低了成本，在单一波长上实现了全光无滤波的可调可切换UWB脉冲，使光纤UWB系统的应用更灵活。

中文关键词： 微波光子；超宽带；无滤波；可调谐；可切换

英文摘要： Ultrawideband (UWB) is a promising technology in short-range, high-capacity wireless communication systems and broadband sensor networks, for it has the advantages of wide band, high speed, low transmitting power, low power consumption and good security performance. However, UWB signal is not suitable for long-distance transmission. But fiber-optic systems have the advantages of low loss and good performance of anti-interference in long-distance transmission. Therefore, it has attracted great attention to generate UWB signal directly in optical domain. Many previous schemes used specially fabricated filters, which increased the costs of the systems. Switchable and tunable scheme has rarely been reported and the generated signal was not at a single wavelength in this kind of schemes. In this project, we will utilize the nonlinear effect of two oppositely transmitted lights in semiconductor optical amplifier to obtain positive and negative Gaussian pulses, then introduce tunable time delays among the pulses, to achieve tunability of pulse width and radio frequency spectrum and switchability of pulse polarity by selecting combination of pulses and adjusting the time delays and optical powers. In this way, we will realize all-optical filter-free tunable and switchable UWB pulses at a single wavelength. The system structure is greatly simplified and the cost is reduced. UWB-over-fiber system will be more flexible by using this method.

英文关键词： microwave photonics;ultrawideband;filter-free;tunable;switchable