在逆向调制(modulating retroreflector,MRR)自由空间光通信(free-space optical,FSO)系统中采用微角锥反射器阵列(micro corner-cube reflector array,MCCRA)作为光学逆向反射器，可以形成伪相位共轭效应(pseudo phase conjugation effect,PPCE),从而大幅降低大气湍流的影响，但是对该典型双程信道的仿真方法、统计模型以及性能分析均未见系统性研究。本文则介绍了一种用于MCCRA信道的双程光波传输仿真的简化方法，并借此仿真方法对采用MCCRA的MRR FSO信道衰落进行统计研究。通过比较双对数正态(lognormal,LN)分布和双伽马-伽马(Gamma-Gamma,GG)分布的复合信道模型，结果显示,双GG模型更适合描述基于MCCRA的MRR FSO双程信道。利用双GG模型评估其系统平均误码率(bit error rate,BER)，证实PPCE带来的性能增益大于信道相关性带来的性能损失。

该文提出了一种新型的宽带近接耦合毫米波微带阵列天线，并将其作为77~81 GHz中远程汽车雷达的专用天线。该天线阵列由微带线及一系列矩形和多边形辐射单元组成。辐射单元在微带线两侧呈周期性分布，间隔约为引导波长的1/2。为增强激励耦合引入了矩形和多边形辐射单元，在拓宽阻抗带宽的同时，抑制了带外频率。不同辐射单元和矩形反射槽相匹配，达到波束赋形的效果，实现了平肩膀辐射方向图。通过调整辐射单元与微带线的间隔，控制辐射单元的归一化电阻。在工作频率为77~81 GHz时，阵列天线的增益超过14 dBi，阻抗带宽达到7.47%(76.5~82.4 GHz)。对实物样本进行加工及性能检测，测试表明，仿真与实测数据基本一致。

A scheme for the generation of a pseudo noise (PN) sequence in the optical domain is proposed. The cascaded units of micro-ring resonator (MRR)-based D flip-flop are used to design the device. D flip-flops consist of a single MRR and share the same optical pump signal. Numerical analysis is performed, and simulated results are discussed. The proposed device can be used as a building block for optical computing and for creating an information processing system.

Wavelength conversion based on degenerate four-wave mixing (FWM) was demonstrated and compared between silicon nanowire and microring resonator (MRR). 15 dB enhancement of conversion efficiency (CE) with relatively low input pump power (5 mW) was achieved experimentally in an MRR. The impacts of bus waveguide length and propagation loss were theoretically analyzed under the effect of nonlinear loss.FosterMA, Turner A C, Sharping J E, Schmidt B S, Lipson M, Gaeta A L. Broad-band optical parametric gain on a silicon photonic chip. Nature, 2006, 441(7096): 960–963

Silicon micro-ring resonators (MRRs) are compact and versatile devices whose periodic frequency response can be exploited for a wide range of applications. In this paper, we review our recent work on linear alloptical signal processing applications using silicon MRRs as passive filters. We focus on applications such as modulation format conversion, differential phase-shift keying (DPSK) demodulation, modulation speed enhancement of directly modulated lasers (DMLs), and monocycle pulse generation. The possibility to implement polarization diversity circuits, which reduce the polarization dependence of standard silicon MRRs, is illustrated on the particular example of DPSK demodulation.He is currently a postdoctoral fellow at the Technical University of Denmark, working on silicon integrated devices for linear signal processing and space division multiplexing.

介绍了逆向调制自由空间激光通信技术的原理和优势。分别对角反射器逆向调制器和猫眼逆向调制器的工作原理进行介绍，归纳这两种逆向调制器的不同实现类型及其特点，对逆向调制器的研究现状进行综述。概括了逆向调制自由空间激光通信技术的应用现状。讨论了逆向调制自由空间激光通信技术的关键技术和技术难点，展望了该技术未来的发展方向和应用前景。