optical

摘要： Optical switching is a fundamental element in all-optical integrated circuits and networks with ultrahigh speed and low energy consumption compared to their electronic counterparts.Switching on/off the waveguiding with another light beam demands large optical nonlinearity to compactify device footprint and decrease energy consumption,which is difficult to achieve in photonic systems.

摘要： Different optical materials used in textiles will show different effects of light response.Fiber optic fabric is a blend of optical fiber and textile fiber.By adding light-emitting diode at the end of fiber with high permeability,it can become self-luminous fiber fabric after electrification.During the day,the effect is the same as ordinary fabric.After being energized in the dark,it will emit dazzling light.

摘要： The original mathematical treatment used in the analysis of the Fizeau experiment of 1851, which measured the relative speed of light in a moving medium, assumes that light travels through the water in a smooth continuous flow, at a speed less than the speed of light in a vacuum (relative to the water). Thus, it assumes that the water’s velocity vector can simply be added to that of the light. However, light is transmitted through optical media, such as water, by a continuous process of charge excitation (semi-absorption) and re-emission by the water molecules;but travels between them at the full speed of light (in a vacuum). Thus, the mathematics describing the process of Fresnel dragging must be formulated differently and can then be explained by classical physics, allowing the entire process to be fully visualized.

摘要： Dear editor,Optical encoder is a kind of angle sensor,which has been applied in a variety of domains such as astronomy,vehicles and industrial production.However,there always exist errors between the measured angles and the real angles,reducing the performance and safety of systems.These measurement errors may raise from various sources.

摘要： Aluminum nitride(AlN)has attracted a great amount of interest due to the fact that these group III–V semiconductors present direct band gap behavior and are compatible with current micro-electro-mechanical systems.In this work,three dimensional(3D)AlN architectures including tubes and helices were constructed by rolling up AlN nanomembranes grown on a silicon-on-insulator wafer via magnetron sputtering.The properties of the AlN membrane were characterized through transmission electron microscopy and X-ray diffraction.The thickness of AlN nanomembranes could be tuned via the RIE thinning method,and thus micro-tubes with different diameters were fabricated.The intrinsic strain in AlN membranes was investigated via micro-Raman spectroscopy,which agrees well with theory prediction.Whispering gallery mode was observed in AlN tubular optical microcavity in photoluminescence spectrum.A postprocess involving atomic layer deposition and R6G immersion were employed on as-fabricated AlN tubes to promote the Q-factor.The AlN tubular micro-resonators could offer a novel design route for Si-based integrated light sources.In addition,the rolled-up technology paves a new way for AlN 3D structure fabrication,which is promising for AlN application in MEMS and photonics fields.

摘要： A theoretical design of a multi-layer for Nd:YAG mirrors resonator is described in this work. An output coupler was designed and fabricated by successive thin layers to achieve very high transmittance at optical wavelengths around 1064 nm for Nd:YAG mirrors resonator. The different film optical filters were used to control the transmittance and reflectance. The three samples of dielectric materials composed of HfO2/Y2O3, Sc2O3 + MgO, and Ta2O5 + TiO2 were used and compared with each other in transmittance, reflectance, full width at half maximum (FWHM), physical thickness, optical thickness, geometric thickness, and incident angles by the software [1].

摘要： Optical waveguide, a physical structure that guides electromagnetic waves in the optical spectrum, is the key elements of photonic devices that perform guiding, coupling, switching, splitting, multiplexing and demultiplexing of optical signals [1]. In general, an optical waveguide is tuned by electrical field through a two-terminal diode [1]. Such integration was widely used in current photonic devices, but restricts its potentials in tiny optical chips for bio/medical and space applications [2].

摘要： 欧洲空间局的新月效应与光瞬变项目(NELIOTA,NEO Lunar Impacts and Optical TrAnsients)的天文学家,一般不到几个小时,就会观测到一次月面闪光现象。这是来自太空的物体以很高的速度撞向没有大气保护的月球的结果。

摘要： Rhodobacter sphaeroides is a purple non-sulfur bacterium that belongs to the α-3 subdivision of Proteobacteria. R. sphaeroides is a model bacterial species because of its complex genome structure and expanded metabolic capabilities. The genome of R. sphaeroides consists of two circular chromosomes and five endogenous plasmids. It has the ability to grow under a wide variety of environmental conditions. It grows aerobically (~20% O2), semi-aerobically (~2% O2), and photosynthetically (under anaerobic condition plus light). It has been previously shown that many bacterial species utilize a number of alternate carbon sources for their optimal growth under a variety of growth conditions. We hypothesize that different or an additional carbon source in the minimal medium differentially affects the bacterial growth under dark-aerobic conditions. The bacterial growth kinetics and the number of cells in the bacterial culture were analyzed by measuring the optical density (OD at 600 nm) and the colony forming units (CFUs) at regular intervals of bacterial cultures. Results reveal that sodium succinate is the preferred sole carbon source for the optimal growth of R. sphaeroides. The results of growth kinetics and CFUs together concluded that from the tested carbon sources, sodium succinate is the best single carbon source in the minimal media for the optimal growth of R. sphaeroides. Interestingly, cell culture grown in SIS supplemented with sodium acetate exhibits a prolonged lag phase with the lowest ODs and CFUs that later switches to the growth-burst phase support previously discovered similar phenomenon of the growth-rate switch in the presence of acetate metabolism. Future work will utilize the aerobically grown R. sphaeroides’ cells as a biocatalyst to deplete the oxygen levels from natural gas streams and industrial gas pipelines.

摘要： This paper deals with the characterization of aerosols in the Sahelian zone, particularly in Burkina Faso based on MODIS observations and in situ measurements of the AERONET network on the Ouagadougou site (12.2°N, 1.4°W). Thus, a seasonal spatial distribution of aerosols made over the period from 2001 to 2016 gives a very great variability of aerosols in Burkina Faso, whose maxima are encountered in Spring, characterized by winds from the North East. This seasonality of aerosols is also shown by the annual cycles of optical, radiative and microphysical parameters measured by AERONET between 1999 and 2006. Moreover, an analysis of these parameters shows the prevalence of mineral dusts characterized by low values of the Angstrom coefficient (α440-870 0.9) and the cooling noticed in the bottom of atmosphere (BOA) and at the top of the atmosphere (TOA). Also, the climatology of the volume size distribution of aerosols shows a very great variability of particles in terms of size influenced by the thin and coarse pattern where most sizes are between 1 and 10 μm.

摘要： In recent years, with the development of communications, communications grid including the formation of digital microwave, fiber optic, wireless and other means of communication has formed. Optical fiber communication with the communication long distance relay, confidentiality, transmission loss, showedtremendous advantages in the communications field, which has become the one of the main pillars of moderncommunication. However, the growing capacity of optical fiber transmission network and increasing bearerservices bring challenges for maintenance of communications cable. The emergence of optical line automaticprotection system made maintenance easier. This article describes the optical protection program, principles,processes, networking, features and advantages, and so on.

摘要： 本发明提供了一种基于EPON(Ethernet Passive Optical Network)的阀值讨论式节能方法，其步骤包括：1、OLT和ONU之间互发MPCP数据帧，完成ONU的加入注册；2、OLT记录所有ONU的状态信息，形成一张状态表并进行周期性的检测；3、把从服务网络接口(SNI-Service Network Interface)来的下行数据帧和ONU来的上行数据帧存储在OLT端的本地缓存器中；4、根据下行数据帧长，上行数据帧长以及预先设置的阀值三者之间的关系，计算出时隙分配方案；5、根据所分配的时隙计算出ONU的下一个轮训周期长度，并推算出睡眠时间(属于该ONU的时隙)和醒来时间(属于其它ONUs的时隙)；6、在OLT端组装新的GATE授权帧，以广播形式向ONU发送；7、OLT与所有ONU进行交互通信直到接收到来自于所有ONU的REPORT报告帧；8、OLT端对ONU状态信息表进行更新；本发明既能考虑到OLT端的数据延迟又能尽最大努力降低能耗，因此能够实现学术上和工业上的期望目标。

摘要： 本公开了一种基于RamanOpticalFiber的半开腔多波长随机拉曼光纤激光器，包括：1080nm泵浦激光器和半开腔随机拉曼光纤激光器。所述1080nm泵浦激光器包括：反射率99.9％的1080nm光纤布拉格光栅，976nm泵浦激光器，(2+1)×1泵浦合束器，NufernLMA‑YDF‑10/130‑M大模场双包层掺镱光纤；所述半开腔随机拉曼光纤激光器包括：1030‑1400nm宽波段光纤全反射镜，OFSRamanOpticalFiber。本发明利用长距离无源光纤中的瑞利散射和受激拉曼散射提供随机分布式反馈和增益放大，可同时输出1至7阶斯托克斯光，实现1.1‑1.6μm的宽光谱覆盖范围，且各阶斯托克斯光光谱强度差值不超过5dB，具有结构简单，输出波长灵活，输出激光时序稳定等特点，可广泛应用于测量、成像以及通信等各个领域。

摘要： 本发明设计一种医学诊断试剂中的分子探针，尤其是涉及一种用于动脉粥样硬化易损斑块诊断的靶向MRI/optical双模态纳米探针的制备方法，该探针由OPN抗体和二巯基丁二酸(DMSA)修饰的磁性Fe3O4纳米颗粒缩合而成，OPN抗体的活性氨基与纳米颗粒表面DMSA的活性羧基通过缩合反应稳定连接。本发明提供用于动脉粥样硬化易损斑块MRI/optical双模态分子影像学成像探针及其制备方法，其将丰富动脉粥样硬化斑块的诊断方法，通过MRI/optical双模态成像技术，识别易损斑块，从而早期预防心血管事件。本发明具有安全可靠的特点，提高了诊断的敏感性和特异性。