Novel construction of a resonant-cavity-enhanced photodetector (RCE-PD) with monolithic high-contrast grating (HCG) is proposed to overcome the difficulty of fabricating a high reflective mirror of RCE-PD at 1 550 nm. In this structure, HCG serves as the top mirror of the RCE-PD, whereas InGaAs serves as a sacrificial layer to achieve monolithic integration. During the bandwidth optimization, the ratio of the thickness of the total intrinsic region and the absorption layer is introduced to realize the simultaneous optimization of the thickness of spacing layers and absorption layer. After structural optimization, the quantum efficiency of the device with diameter of 20 μm is 82% at 1 550 nm, and the 3-dB bandwidth is 34 GHz at a bias of 3 V.

针对行波光电探测器阵列(TW-PDA)的传输时延导致各路电信号在输出终端产生相位失配，影响整体频率响应的问题，提出了一种叉状光电探测器阵列(F-PDA)的电极结构.该电极采用对称连接结构代替TW-PDA的逐级连接结构的方法，使得各路光电探测器单元与信号输出终端的距离保持一致，从而克服传统结构中由于传输时延带来的一系列问题.电极的结构参数经HFSS进行设计并优化后，在100 GHz内的最大插入损耗不超过1.5 dB，特征阻抗稳定于50Ω 左右.实验结果表明，制备的TW-PDA在40 GHz下的插入损耗约2.5 dB，3 dB带宽约6.9 GHz; 而F-PDA对应的测试结果分别约1.36 dB以及13.8 GHz.相比而言，本文提出的结构存在明显的性能提升.

为了简化和改善光载无线通信系统, 提出了一种光探测器偏压调制技术, 利用PIN光探测器(PIN-PD)和单行载流子光探测器(UTC-PD)的输出光电流随偏压变化的特性进行调制.采用光探测器偏置调制技术, 光电探测和调制可以在一个光探测器上同时实现.研究表明当入射光功率为2.93 dBm 时, PIN-PD在10 GHz射频副载波上的调制带宽为800 MHz, UTC-PD在150 GHz射频副载波上的调制带宽为18.75 GHz.调制带宽随入射光功率的增大而增大, 当入射光功率为12.93 dBm时, UTC-PD在150 GHz射频副载波上的调制带宽可达25 GHz.调制深度与正弦偏压调制信号的最小值有关.

In this paper, we propose and experimentally demonstrate an auto-bias control scheme for stabilizing a lithium niobate (LN) Mach-Zehnder modulator (MZM) at any operating point along the power transmission curve. It is based on that the bias drift would change the operating point and result in varying the output optical average power of the Mach-Zehnder modulator and its first and second derivatives. The ratio of the first to the second derivative of the output optical average power is used in the proposed scheme as the key parameter. The experimental results show that the output optical average power of the LN MZM hardly changes at the desired operating point, and the maximum deviation of output optical average power is less than ±4%.

A novel scheme employing low-density parity-check (LDPC) codes in atmospheric optical communication system is proposed. We deploy coherent detection at the receiving side in the proposed scheme. To reduce bit error rate (BER) and enhance the system performance, LDPC codes are exploited and coherent receiver is used to improve the receiving sensitivity. Experiments are implemented to evaluate the performance of the transmission system. The atmospheric channel attenuations are set to 20-30 dB/km. The coherent detection with LDPC codes can reduce the received power requirement by ~4 dBm at the BER of 10^-9.

介绍了基于OADM 网元管理系统的CORBA 分布式网络管理接口的设计，并给出推模式下传递结构化事件的具体实现过程。在遵循TMF814 接口集的网络管理系统中，该网元管理系统及其网络管理接口能够实现设备的本地管理和分布式网络管理，有助于多种设备共存的光通信网络实现统一管理。

利用高非线性光子晶体光纤中的自相位调制效应产生的超连续谱,理论上推导了超窄脉冲信号的再生机制。分别从频域和时域上形象的解释了脉冲再生的原理,该本再生方法可以适用于OTDM的信号再生。实验上对劣化了的脉冲宽度为1.7ps的携带信息的超窄脉冲信号进行了再生,再生之后的信号峰值均衡,消光比达到了15dB。再生前信号中心波长是1548.2nm,重复频率是9.96872GHz。实验中,在1554nm-1570nm和1530nm-1543nm范围内都可以得到10dB以上的再生质量。同时拟合了信号峰值功率和波长关系,得到的曲线和超连续谱曲线相吻合。

采用矢量波束传播法 (BPM) 对不同结构参量的光子晶体光纤的色散和非线性特性进行数值 分析,计算色散平坦光子晶体光纤的参量色散系数D, 有效模场面积 Aeff 和非线性系数γ。分析D, γ与色散平坦光子晶体光纤结构参量空气孔间距Λ、空气孔直径d 之间的关系。分析结果表明,调节色散平坦光子晶体光纤的结构参量可以灵活地调整色散和非线性特性。得到的色散平坦光子 晶体光纤在1300~1600 nm波长范围内,色散值仅在 -1.5 ps?kmˉ1?nmˉ1左右,非线性系数都大于 19 Wˉ1?kmˉ1。

对耦合微环谐振腔光波导中的有限尺寸效应进行了研究.在CMROW两端引入抗反射结构，采用数值方法对抗反射中的三个交叉耦合系数进行了优化，消除了透射谱和群时延谱的有限尺寸效应.数值计算得到了弱耦合和强耦合情况下抗反射结构中优化交叉耦合系数的拟合公式,可以直接计算出消除有限尺寸效应时所需的优化参量.