An optical fibre sensor for use in a tissue cutting tool

This pre-study investigates a fibre optic alternative to more conventional sensors for measuring force indirectly as bending or deflection in a medical robotic application. The paper discusses problems regarding the integration of fibre optics into a cutting tool for the removal of prostate gland tissue. The aim is to integrate the sensor in a tube rod with an inner diameter of 0.6 mm and use it as a force feedback sensor for the control system of the robot. The paper proposes and evaluates an inexpensive opto-mechatronic device for launching light into and detecting light received from an optical fibre. A simple sensor prototype is constructed to show the feasibility to use a fibre optic sensor for the prostate gland cutting tool.     

A Skin‐Inspired Integrated Sensor for Synchronous Monitoring of Multiparameter Signals

Electronic skins, as the integration of multiple distinct sensors, have aroused broad interests owing to their great potential in sensing applications. However, problems including the interference between sensing components and the difficulty in synchronous monitoring are practically encountered when they are applied to mixed signals. In this work, efforts are devoted to trouble‐free technical strategies for laminating three sensors with different sensing abilities into a skin‐like electronic device. The use of ionic liquid, combined with particular circuit topologies, ensures the reliable stability against mechanical disturbance during the real‐time sensing tests. The intrinsic layered structure and three independent sensing functions of natural skins are successfully presented by this particular device in which three sensors with the ease of preparation are spatially integrated. The changes of temperature, pressure, and infrared light can be recorded simultaneously yet without mutual signal interference. The perfect integration of multiple functional sensors into a single skin‐like device without any signal interference makes an important progress for pursuing the goal of future electronic skins that can practically be used as skin.     

Multiple quantum well (MQW) waveguide modulators

Because the electroabsorption effect in semiconductor multiple quantum well material is approximately 50 times larger than in bulk semiconductors, significant interest has been generated in the use of MQW's in optical modulators. Small high-speed devices have been made which show promise for external modulators in optical transmission systems, as well as for encoding and processing components in optical interconnect and signal processing systems. The fact that these modulators are made from III-V semiconductors had led to interest in integration of these components with other active optoelectronic components. Although most devices have operated with light of a wavelength of 0.85 μm, recently much progress has been made in applying this technology to devices operating near 1.55 μm. The author reviews the work of the last few years in this field and indicates some future directions     

基于图像处理的光电传感器光路检测与调整方法研究

提出了一种基于图像处理的反射式强度调制型光电传感器光路调整方法.考虑了光源光阑等器件对光路的影响,利用面阵CMOS器件采集传感器出射光斑的图像,并通过图像处理的方法分别计算光斑的几何中心与能量中心,得到偏心误差值,以此为依据调整传感器光路,达到改善光斑光强分布的目的.文中对测量系统、调整方法、光斑参数计算等做了详细说明,并给出了调整前后的光斑图像.试验结果表明,这种方法的测量原理简单、测量精度高,可以有效地改善传感器的光强分布状况.     

A Bioinspired Wireless Epidermal Photoreceptor for Artificial Skin Vision

Skin vision can be found in many invertebrates, such as earthworms, jellyfish, and octopuses using light‐sensitive rod cells in the skin. It enables optical perception and colorimetric responses, providing intriguing capabilities that human skin does not have. A bioinspired wireless, battery‐free, artificial skin vision (ASV) device consisting of flexible optical and optoelectronic components which essentially mimic the hierarchical structures and biological functions of rod cells in a skin‐like configuration for light sensing and signal processing is developed. The ASV device can collect sweat with integrated microfluidic channels and allow real‐time measurement of on‐skin fluids by monitoring the intrinsic optical properties via a customizable microprism light filter. The device also shows sensitive colorimetric responses to input stimulus at chosen detection wavelengths and demonstrates a capacity for in situ quantitative analysis of biomarkers in sweat through alternative colorimetric light filters. Multiple ASVs together create a body area network with a collection of wireless sensors that can work in parallel to acquire multidimensional human physiological signals and predict fitness variations using a specified deep learning neural network. The system has potential applications in biomimetic engineering, physiological monitoring, and intelligent personalized diagnostics.     

A fiber-optic hydrophone with a mechanical anti-aliasing filter

Two fiber-optic hydrophones which use high birefringence fiber have been constructed and tested. The hydrophone sensitivity, as determined by optical interferometry, was 93.5 mrad/Pa at 100 Hz. One of the hydrophones tested had an integral low-pass filter which had a break point near 200 Hz and a measured roll-off of 26 dB/octave. This hydrophone transducer is a prototype device for a class of sensors that can be optically sampled. Fiber sensors that are optically sampled require mechanical anti-aliasing filters to remove high frequency components. Optical frequency multiplexing of a number of fiber sensors which are connected in series is expected to be an important application for this type of sensor.     

Fine Tuned Nanolayered Metal/Metal Oxide Electrode for Semitransparent Colloidal Quantum Dot Solar Cells

Semitransparent photovoltaics have great potential, for example, in building‐integration or in portable electronics. However, the front and back contact electrodes significantly affect the light transmission and photovoltaic performance of the complete device. Herein, the use of a semitransparent nanolayered metal/metal oxide electrode for a semitransparent PbS colloidal quantum dot solar cell to increase the light transmission and power conversion efficiency is reported. The effect of the nanolayered electrode on the optical properties within the solar cells is studied and compared to a theoretically model to identify the origin of optical losses that lower the device transmission. The results show that the light transmission in the visible region and the photovoltaic performance are significantly enhanced with the nanolayered electrode. The solar cell shows an efficiency of 5.4% and average visible transmittance of 24.1%, which is an increase by 28.6% and 59.6%, respectively, compared to the device with a standard Au film as the electrode. These results demonstrate that the optical and electrical modification of transparent electrode is possible and essential for reducing the light reflection and absorption of the electrode in semitransparent photovoltaics, and, meanwhile the demonstrated nanolayered materials may provide an avenue for enhancing the device transparency and efficiency.     

A simple monolithically integrated optical receiver consisting of an optical preamplifier and a p-i-n photodiode

We demonstrate a monolithic optical receiver consisting of the integration of a semiconductor optical amplifier and a p-i-n photodetector based on asymmetric twin-waveguide technology. Multiple quantum wells with 1% compressive strain are used for both optical amplification and detection. The device has a peak external responsivity of 8.2/spl plusmn/0.4 A/W (/spl sim/9-dB fiber-to-detector gain), and a 3-dB optical bandwidth of 11/spl plusmn/1GHz, equivalent to a 265-GHz gain-bandwidth product. The efficient coupling of light between individual optical components is achieved by a lateral adiabatic taper that reduces the fabrication complexity. This work represents a considerable simplification over previously demonstrated high-performance integrated optical receivers.     

可见光通信集成接收机研究

可见光通信技术的推广很大程度上取决于低成本接收机的制备能力,该制备包括光学、光子、电路等元件以及上述元件的集成.文中提出了一种低花费的集成接收机制作方案,提出了一种新型的基于引线键合技术的二维光电检测阵列制备方法,并对光电器件、光学系统的选择,分集接收电路设计思想及其光电集成方案作了详细描述,为下一步的具体制备打下基础.     

具有光束偏转功能的亚波长光栅偏振分束器

针对亚波长光栅偏振分束器无法实现垂直出射光 、集成耦合效率低的问题,本文设计了 一种具有光束偏转功能的亚波长光栅偏振分束器,可实现偏振分束且能获得垂直出射光。器 件上 层采用光栅衍射理论设计了可实现偏振分束的周期亚波长光栅,下层通过严格耦合波法与波 前相 位控制理论设计了具有光束偏转功能的非周期亚波长光栅。基于有限元软件COMSOL对设计 的器 件进行仿真分析,结果表明该器件可分开TE与TM混合偏振光且能实现光束垂直出射,两种 偏振 光的总透射率在1550nm处超过了76.5%,偏振 消光比为14.0 dB。因此通过该偏振分束器不但可 以获得垂直出射的单偏振光,而且能有效提高垂直耦合型器件的工作效率,有望应用在面向 光纤通信的集成光电器件中。     

模拟路灯控制系统设计

模拟路灯控制系统以SCT89C58为控制核心。以DS1302为时钟源,以红外线传感器、光学传感器对移动物体和环境明暗变化进行信息采集,通过软件编程能实时显示时钟和设定、显示开关灯时间,控制整条支路根据设定时间、环境明暗、交通情况自动开灯、关灯、调节亮灯状态或独立控制单灯开和关,并能根据布设在支路单元上的光敏器件的采集信息进行路灯故障声光报警。在设计中编程语言使用了C51,并采用模块化设计方法 ,不仅易于编程和调试,也可减小软件故障率和提高软件的可靠性。因此,本系统具有性能优良、稳定可靠、节能环保的优点。     

Optical displacement measurement with GaAs/AlGaAs-basedmonolithically integrated Michelson interferometers

Two monolithically integrated optical displacement sensors fabricated in the GaAs/AlGaAs material system are reported. These single-chip microsystems are configured as Michelson interferometers and comprise a distributed Bragg reflector (DBR) laser, photodetectors, phase shifters, and waveguide couplers. While the use of a single Michelson interferometer allows measurement of displacement magnitude only, a double Michelson interferometer with two interferometer signals in phase quadrature also permits determination of movement direction. In addition, through the use of two 90° phase-shifted interferometer signals in the latter device, a phase interpolation of 2π/20 is possible, leading to a displacement resolution in the range of 20 nm. The integration of these complex optical functions could be realized with a relatively simple fabrication process     

Components for optical communications systems: A review

Current trends in research and development of components for optical communication are reviewed. Emphasis is placed on active components for fiber-optic systems which have undergone recent major advances. Basic properties of optical fibers and recent technological improvements in splices, connectors, and source/detector-fiber couplers are presented first. This background information serves as a basis for describing recent developments in optical sources (e.g., device reliability, LED's and laser diodes) and photodetectors. Developments in both the 0.8-0.9-µm and 1.0-1.7-µm wavelength regions are covered. Also surveyed are results of research in areas of potential interest for optical communications: novel fiber-optic components, integrated optics (sources and modulators/switches), novel device fabrication methods, and integration of optical components.     

Flexible and Stretchable Smart Display: Materials,Fabrication, Device Design,and System Integration

Recent technological advances in nanomaterials have driven the development of high‐performance light‐emitting devices with flexible and stretchable form factors. Deformability in such devices is mainly achieved by replacing the rigid materials in the device components with flexible nanomaterials and their assemblies (e.g., carbon nanotubes, silver nanowires, graphene, and quantum dots) or with intrinsically soft materials and their composites (e.g., polymers and elastomers). Downscaling the dimensions of the functional materials to the nanometer range dramatically decreases their flexural rigidity, and production of polymer/elastomer composites with functional nanomaterials provides light‐emitting devices with flexibility and stretchability. Furthermore, monolithic integration of these light‐emitting devices with deformable sensors furnishes the resulting display with various smart functions such as force/capacitive touch‐based data input, personalized health monitoring, and interactive human–machine interfacing. These ultrathin, lightweight, and deformable smart optoelectronic devices have attracted widespread interest from materials scientists and device engineers. Here, a comprehensive review of recent progress concerning these flexible and stretchable smart displays is presented with a focus on materials development, fabrication techniques, and device designs. Brief overviews of an integrated system of advanced smart displays and cutting‐edge wearable sensors are also presented, and, to conclude, a discussion of the future research outlook is given.     

A Two-Wafer Approach for Integration of Optical MEMS and Photonics on Silicon Substrate

This letter reports a novel two-wafer approach which demonstrates an integration of optical microelectromechanical system (MEMS) devices and photonics on a silicon substrate. The great advantage of this novel wafer bonding scheme is the ability to maintain the optical axis of the optical MEMS device at the same axis as the optical components. The bonded two wafers which are partially processed, which allows for further processing on the wafer after bonding. Thus, the critical alignment issue is resolved for devices requiring precise alignment in x-/y-/z-axis. Individual functionalities of optical MEMS device and optical coupling between silicon waveguide, fibers and ball lens are demonstrated. This technology shows the potential for integrating silicon photonics integrated circuit and MEMS components with reconfiguration functions on a single silicon substrate.      

Bioinspired Artificial Eyes: Optic Components,Digital Cameras,and Visual Prostheses

The diverse vision systems found in nature can provide interesting design inspiration for imaging devices, ranging from optical subcomponents to digital cameras and visual prostheses, with more desirable optical characteristics compared to conventional imagers. The advantages of natural vision systems include high visual acuity, wide field of view, wavelength‐free imaging, improved aberration correction and depth of field, and high motion sensitivity. Recent advances in soft materials, ultrathin electronics, and deformable optoelectronics have facilitated the realization of novel processes and device designs that mimic biological vision systems. This review highlights recent progress and continued efforts in the research and development of bioinspired artificial eyes. At first, the configuration of two representative eyes found in nature: a single‐chambered eye and a compound eye, is explained. Then, advances in bioinspired optic components and image sensors are discussed in terms of materials, optical/mechanical designs, and integration schemes. Subsequently, novel visual prostheses as representative application examples of bioinspired artificial eyes are described.     

多通道光纤加速度测试分析系统的研究

系统把微机电加速度敏感芯片与光纤传感技术相结合,技术上发展了基于微机电技术的光纤加速度传感器敏感部件的集成、批量制造技术;通过采用光开关和多组光同步分路器、分组切换电子开关和多通道同步数据采集器的组合,实现大容量测量通道数扩展。解决了传统光纤传感器向微型化和批量生产时遇到的装配困难及光纤传感器难以实现大容量高速同步采集的问题。     

Integrated-optic implementation of a confocal scanning opticalmicroscope

A confocal scanning optical microscope implemented in an integrated-optic structure is demonstrated. The compact nature of the device proves to be more suitable for environments where mechanical shock can result in optical misalignment of discrete components. The device is implemented in a thin-film optical waveguide with optical fiber connections for light input and output. An objective lens and focusing beam splitter are incorporated into the waveguide structure to form the sensing head of the microscope. The fabrication of the device is discussed, and both intensity and differential contrast images are presented to demonstrate the device operation. The confocal imaging characteristics of the microscope are also demonstrated     

Strain evaluation of epoxy-cured fiber-optic connectors

Optical fiber connectors are passive components used to link two fiber links or a fiber link to a photonic device. One widely used type of fiber connector, a design that uses a thermally cured epoxy adhesive, has been evaluated via Bragg grating-based fiber strain sensors. Strain sensors were used to evaluate the strain incurred by the optical fiber as a result of installation and subsequent environmental testing. Preliminary mechanical modeling and a strain analysis using Bragg grating-based strain sensors are discussed. Since the strain sensors were not exposed to uniaxial loading, mechanical modeling was used to determine the optimum placement of the sensors and the expected response. Also discussed are ongoing studies to evaluate the viscoelastic behavior of the epoxy and its effect on the strain state of the connector assembly.     

Development of medical pressure and temperature sensors employingoptical spectrum modulation

Fiber optic Fabry-Perot sensors have been developed whose optical reflectance varies with optical cavity depth (pressure) or with change in a material's refractive index (temperature). These sensors employ a unique combination of features: they are interrogated by an LED; they are designed to operate within a single reflectance cycle; and their returned light is analyzed by a dichroic ratio technique. The sensors use a step index glass fiber and are relatively insensitive to absolute light levels and fiber bending. They have an expanded linear operating range and can be built for low cost disposable applications. Sensor performance meets or exceeds established medical requirements.