在新型掺钪(Sc)氮化铝(Al1-xScxN)集成光学平台上设计了插入损耗低、传输通道谱线平坦的O波段四通道波分(解)复用器, 并提出了优化方法。所设计的器件结构基于级联马赫-曾德尔干涉仪(MZI)滤波器, 结合弯曲波导结构的定向耦合器改善波长敏感度。针对粗波分复用(CWDM)应用的特性, 文章使用粒子群算法(PSO)提升器件性能优化的效率, 通过调整器件结构的设计参数对四路通道的传输谱线质量进行优化。针对0%, 9%, 23%的掺Sc浓度, 设计的解复用器表现出宽达约15.6nm的1-dB带宽和小于0.1dB的插入损耗, 传输谱线呈“盒状”响应, 各通道间串扰均优于-30.6dB。

该文介绍了一种基于马赫-则德尔干涉仪(MZI）与二甲基硅油(DSO)相结合的高灵敏度光纤温度传感器。传感器由MZI及填充在其表面的DSO组成。MZI由单模光纤-锥形无芯光纤-单模光纤构成。填充DSO后，MZI的谐振峰向右有小的漂移。通过跟踪MZI谐振峰波长随温度的变化，对环境温度进行测量。经测试，传感器的温度灵敏度为-97.7 pm/℃，而未填充DSO的MZI温度灵敏度为-50.1 pm/℃，传感器灵敏度提高了约1.95倍。该传感器具有结构制作简单，造价低及灵敏度高等优点，具有一定的应用前景。

We propose and demonstrate an all-fiber liquid-level sensor using an in-line multimode-single-mode-multimode (MSM) fiber structure. A piece of single-mode fiber (SMF) is spliced to two sections of equivalent multimode fiber (MMF) which are used as both mode splitter and mode coupler. The cladding mode will be excited when the light propagates from MMF to SMF, and then it will be combined with fundamental mode to form a Mach-Zehnder interferometer (MZI) when the light propagates from SMF to the other MMF. The liquid level is detected by the selected resonant dips shift of the transmission spectrum. A sensing sensitivity of 264.6 pm/mm is achieved for the proposed sensor with an SMF length of 26 mm. Due to its compact structure, easy fabrication, and high sensitivity, the proposed liquid-level sensor is attractive for practical applications in a variety of fields, such as marine detection and chemical processing.

提出了一种基于平面光波导工艺的带有可调定向耦合器的非对称MZI结构.模拟结果显示，当定向耦合器的两个耦合臂的折射率独立改变时，定向耦合器的调制效果较好；当调制电极与耦合区的波导间距为0时，两个耦合臂的温度差达到最大.测试得到，AMZI的插入损耗为2.05 dB，延迟时间为151.4 ps，脉冲对的功率比近似为1.该器件有助于提高集成QKD器件的性能.

移相器是一种常用的集成光学结构, 其相移值的波长相关性决定了移相器的工作波长范围。针对移相器的波长相关性, 文中对两种集成光学移相器设计方案(长度差方案和折射率差方案)所设计的二氧化硅基集成光学移相器进行了实验研究。在马赫-曾德尔干涉仪(MZI)的两干涉臂之间, 采用两种移相方案分别设计制作180°移相器, 通过测试MZI的插入损耗与波长的依赖关系对两种移相器的波长相关性进行了比较。研究结果显示, 折射率差方案所设计移相器的工作波长范围大约是长度差方案的1.8~1.9倍。这一实验结果与理论计算吻合, 证明了折射率差方案设计的移相器的相移值波长相关性更小, 因而具有更宽的工作波长范围。

This paper firstly and experimentally demonstrates an in-fiber axial micro-strain sensing head, combined with a Mach-Zehnder interferometer (MZI) based on the concentric multilayer elliptical-core fiber (CMECF). This MZI with a high extinction ratio (about 15 dB) is successfully achieved with a CMECF-single mode fiber-CMECF (CSC) structure. The MZI sensor theory and the resonance demodulation technology are systematically described in this paper. In this CSC structure, two sections of the CMECF have a role as the mode generator and coupler, respectively. LP01 and LP11 even, which have similar excitation coefficients, are two dominated propagating mode groups supported in the CMECF. On account of the distinct dual-mode property, a good stability of this sensor is realized. The detected resonance in the MZI shifts as the axial micro-strain variated due to the strong interaction between higher order modes. High sensitivity of ~1.78 pm/με is experimentally achieved within the range of 0 με - 1250 με, meanwhile, the intensity fluctuation is below 0.38 dB.

提出了一种基于复合光纤滤波器的在室温下稳定输出多波长掺铒光纤激光器, 该激光器由两个级联球状结构的马赫-增德尔干涉仪(MZI)和一个双折射光纤滤波器-Lyot滤波器组成。球状结构MZI是由光纤熔接机在一段单模光纤(SMF)放电设计而成的。Lyot双折射光纤滤波器是利用一段保偏光纤(PMF)和两个偏振控制器(PC)连接而成, 该结构可以诱导非线性偏振旋转效应和双折射光纤效应来抑制模式竞争产生多波长。Lyot滤波器和球状结构的MZI作为模式限制器件, 并且Lyot滤波器对级联球状结构MZI的透射谱进行调制, 其透射谱周期决定了复合滤波器结构的透射谱周期。在室温下, 该系统实现了边模抑制比约为40 dB的九个波长的同时激射, 且波长间隔约为0.68 nm, 与Lyot滤波器透射谱周期一致。为了验证输出波长的稳定性, 在2 h内, 每隔10 min观察输出的波长, 实验证明, 室温下中心波长输出功率的浮动小于0.67 dB。此外, 将两个球状结构MZI放置在高温炉上, 使其外界温度从30 ℃升至110 ℃时, 输出波长光谱的调谐范围可达到6.69 nm。