Various optical fibers are used for a wide range of applications from submarine cable transmission over 10,000 km to indoor wiring less than 1 m. It is therefore important to develop and commercialize novel fibers dedicated to each of these applications.
We have developed bend-insensitive fibers which have low bending losses. At a small bending radius, the bending loss of the bend-insensitive fibers is more than one order of magnitude smaller than that of a conventional single-mode fiber with a step-index profile. The application areas of bend-insensitive fibers are expanding, because they can avoid communication failure due to fiber bending during fiber installation.
Fujikura leads the development of multi-core fiber, in which multiple cores are embedded in the cladding. The multi-core fiber can make a breakthrough in the transmission capacity and thus has attracted much attention as a novel optical fiber for long haul optical communication.
Rapid growth of FTTH network installation stimulates the development of new optical fiber cables suitable for economical construction of FTTH. The technical points for this are as follows: (1) efficient use of existing facilities, (2) cost reduction of network construction, (3) establishment of cable installation technology in places where cable installing is difficult or impossible. This paper presents details of the latest optical fiber cable technologies for further expansion of FTTH network.
The applications for video delivery, cloud services, etc. are becoming more diverse day by day, the communication capacity is growing year by year, and the importance of the optical access network is getting higher and higher, all of them aimed at the realization of a ubiquitous network society. The optical access network, which is an indispensable communications infrastructure in today’s world, requires high speed & large capacity, high reliability, electrical power saving, and low cost. In this paper, we present the fiber optics and optical cable network components for the support of these infrastructures.
Fujikura has developed a variety of optical transceivers for telecommunication, optical access network, and data communication. We also have developed optical transmission equipment such as a media converter, video transmission equipment, PON equipment for FTTH, and an apparatus for a virtual private network (VPN). This paper reviews recent developments of the above equipment and modules; (1) 40 Gbit/s RZ-DQPSK transponder for optical transport networks, (2) AOC (active optical cable) for data centers and manufacturing facilities, and (3) VPN apparatus that realizes VPN connection over the wide-area IP network.
In the 1980s, Fujikura started to apply its optical communication technology to other fields such as manufacturing and medical industries. We call those products for the new application "Applied Optics Products". Today, novel technologies including advanced photonics, semiconductor technology and electronics are incorporated into the applied optics products, and they have been deployed to new markets.
The essential requirements for establishing a low-loss and high-speed telecommunication line using optical fibers are high performance and quality splicing technology. The simple connection of optical fibers using optical connectors and mechanical splices is increasing. However, the fusion splice is needed for long-haul and high-capacity trunk communications such as submarine optical fiber cable. This requires not only ultra low loss and low back reflection, but also long-term reliability and strength of the fusion splice. The fusion splice is also used when splicing specialty optical fibers for light amplification and high power laser transmission for use in various medical procedures or machining applications. In addition to the splicing technology, fiber cleaving and splice protection technologies are also important steps in the splicing process. In this paper, we introduce the features of each technology owned by our company.
Fiber lasers have attracted much attention in recent years. Fujikura has compiled all of the optical technologies required for fiber lasers, and researched intensively on fiber lasers in terms of their sophistication and commercialization. This report introduces Fujikura's fiber laser prototypes and products on high-power pulsed fiber lasers, high-power continuous-wave fiber lasers, and fiber lasers for wavelength conversion, and describes original and advanced results from Fujikura's research and development activities corresponding to these fiber laser categories.
"Fiber-optic sensing" is the important element of the lightwave sensing technology. Since the fibers also work as "sensors", various measurement techniques and various specialty fibers which are optimized for each specific objective are required. In this paper, recent progress in the measurement techniques and the specialty fibers for the lightwae sensing are reviewed.
Flexible printed circuit (FPC) boards are used for various electronic devices. As electronic devices reduce in size and thickness and increase in functionality, FPCs evolve. Among various FPCs, those assembled in mobile devices predominantly consisting of mobile phones require a leading-edge technology. In this paper, we report the current progress status of semi-additive FPCs, high-speed data transmission FPCs, and an FPC assembly technique among new technologies and products Fujikura works on.
This report introduces Fujikura's all-polyimide IVH (interstitial Via Hole)-multi-layer circuit boards and device-embedding technology. Employing thin polyimide film as insulation layers, the boards using these technologies feature a very thin structure and excellent reliability. As IVHs connecting adjacent layers are filled with special conductive paste, this allows highdensity wiring, as well as simple fabrication. In addition, the embedding technology enables various 3D arrangements of LSIs and passive components in a multi-layer circuit board. IVHs and embedding technology will enable drastically reduced size of circuit board and the shortest signal path and thus accelerate miniaturization and increase in performance of electronic devices.
Fujikura is working on the development of value-added products of internal and external interface components (cable assembly, antenna, carriage, etc.) for electronic devices with reductions in size and weight, high-speed transmission and ecology as the keywords. This report describes Fujikura's development of micro coaxial assembly, film antenna and high-speed transmission cable.
Recent years have seen a worldwide explosive growth of various mobile electronic devices such as a smart phone, a tablet terminal and an AV equipment. Achieving key features not only expanded functionality but slim and smart design are essential to these mobile electronic devices. To that end it is indispensable for the electronic components used in those devices to be compact and lightweight as well as to have high functionality.
DDK Ltd. manufactures and sells connectors for such devices for many years. These days especially it has become more and more important for us to research and develop connectors by being in advance of the electronic device technology which progresses quickly and continually.
In this paper we will explain the features of our typical connectors using the examples and introduce part of the technology which we have so far created.
We have been manufacturing and selling membrane switches, as a herald of printed electronics, for approximately thirty years. This paper describes the trends of the membrane switches used in various markets and progressive printed electronics technologies such as advanced printing and surface mounting technologies.
Fujikura has been manufacturing a variety of sensors along with requests from the fields of telecommunications, automotive, medical and consumer electronics. In this paper, we introduce new type sensors that have been developed using the latest Micro Electro Mechanical Systems (MEMS) technology. The MEMS technology refers to technology to integrate micrometer-sized mechanical elements, sensors, actuators and electronic circuits, on a single substrate such as silicon, glass or organic materials.
Currently, we are developing an ultra-compact digital output absolute pressure sensor, a through-silicon via (TSV) package for image sensor and a thin film fluxgate type magnetic sensor, using the MEMS technology. We also report their features and performance.
Thin heat pipe modules are widely used for cooling the CPU of a PC or electronic devices. To meet customer demands for improvement in thermal performance and reduction in size and height, we have developed an ultra-thin (1mm) heat pipe. In addition, we have worked on the development of an ultra-thin (1mm) piezo fan included in the cooling module. Another product we developed is a water-cooled module having a special channel structure for a power semiconductor device of a power converter used for wind or solar power generation requires a water-cooled system to help increase the converter capacity. As the power consumption of datacenters or super computers has been increasing, increases in efficiency of cooling facilities and reductions in power consumption are absolutely necessary. So far, the air cooling system has been predominantly adopted in this field, but currently water cooling system is being reconsidered as an efficient cooling system. We also completed the development of a cold plate unit, which has a micro channel structure, for cooling super computers. After making the prototypes, the performance of the system met customer demands, and our products have contributed not only to the highest calculation speed but also to reductions in the power consumption of CPUs.
The weight of a wiring harness is increasing year by year because of newly added functions. In recent years, there are growing customer demands for environmentally friendly products, such as high-voltage wiring harness systems, for hybrid electric vehicles (HEVs) and electric vehicles (EVs) and weight-saving wiring harnesses systems designed to improve fuel efficiency. In order to satisfy these customer demands, we are developing a high-voltage wiring harness system and weight-saving electric wire and connection technology for a weight-saving wiring harness system. Although the gross weight of the wiring harness using a conventional electric wire is about 30 kg/car, weight savings of about 30% is possible by using a weight-saving electric wire.
The number of automotive electronic components is increasing year by year because of newly added functions. In addition to miniaturization and weight-saving needs, safety-related customer needs, in particular, are growing recent years. To satisfy these customer demands, we are developing an advanced passenger detection sensor with membrane circuits which are one of our core technologies in addition to the current seatbelt reminder sensor which can distinguish a passenger from loads. Our advanced passenger detection sensor has the longdistance detection capability of a world top level and can dynamically detect the passenger is in the dangerous zone at the time of air bag deployment.
As buildings in cities have become higher and more intelligent, elevators serving as a vertical traffic line have become increasingly important. An elevator cable for a skyscraper requires the increased number of core wires, reduction of weight and ensuring safety. With increase of information to be transmitted, we have encouraged development of super multicore elevator cables. Additionally, we have developed a sheath material for lightweight elevator cables with lower smoke emission rate during burning. A halogen-free flame-retardant elevator cable using this sheathing is about 20 percent lighter than a conventional elevator cable. The smoke emission rate of this cable is 60 percent lower than that of a conventional cable.
Fujikura's halogen-free flame-retardant elevator cable that we will report on later has been recently adopted for superfast elevators installed in skyscrapers.
The conventional leaky coaxial cable (abbreviated as LCX hereinafter) is designed on the premise that it is used for long distance where the cable is laid inside a tunnel, along railroad, etc. In order to obtain low transmission loss, outer diameter is as thick as 15 to 60 mm, making it heavy. Therefore, special technology is required for cable laying work. However, recently, there have been growing needs for employing LCX as an antenna for wireless LAN, which can be installed easily and whose communication can be limited to short ranges such as within an office or conference room.
Fujikura has developed a thin and lightweight LCX-5D that is able to secure a stable communication area near LCX, whose outside diameter is 7 mm and whose weight is 65 g/m. We evaluated electrical characteristics, including electromagnetic wave radiation characteristics, environment resistance, and mechanical characteristics, and confirmed the superior performances.
In recent years, as an alternative energy source to fossil fuels such as oil, wind power generation, which is a renewable energy source, is attracting increased attention and lots of wind power farms are being built within the country and overseas. We started development of cable and accessories for wind power generation from around 2000, and have already supplied them to many wind power plants. Here, we give you an introduction to the wind power plant equipment and distribution systems we have developed.
Since an electric vehicle has an effect on greenhouse gas (CO2) reduction, which contributes greatly to preventing global warming, the use of electric vehicles is considered to be expanded increasingly from now on. For the spread of electric vehicle, infrastructure improvement for charging is indispensable. An easy-to-use connector with a lead cable for a charger, which can be used not only by a specific person but also by men and women of all ages, needs to be developed so that charge operation does not become an obstacle to the spread of electric vehicles. Paying attention to (1) small manipulation force and (2) simple operation, we adopt a lever method to enable operation by small force, using the principle of leverage for movement. Moreover, we developed such a connector, focusing on angle of grip and operation method of the lever. Also, in order to ensure user safety, we adopted a cable compliant with the Electrical Appliance and Material Safety Law, and the connector has a structure where electric locking is provided so that it may not accidentally drop off during charging.
Various characteristics of a metal cable are required depending on the application. In recent years, consideration to the environment is strongly demanded in design and manufacturing of products. In addition to accordance to RoHS or REACH, the environmental load reduction such as eliminating halogen, energy saving and recycling are also critical issues. This paper describes Fujikura's recent development of materials compatible to the environmental requirement.
The demand for clean power source is increasing for solving environmental issues. We have developed 1 kW output direct methanol fuel cell (DMFC) successfully, which is the highest output level in the world in this kind of fuel cell. Methanol, the fuel of DMFCs, has such advantage features as easy handling, high storage stability and high energy storage capability. The exhaust heat from fuel cell is recovered for hot water supplying for customer. The total system energy conversion efficiency is more than 80 %. It can be applied to various markets.
A dye-sensitized solar cell (DSC) has unique properties that the cell performance does not readily decrease even at higher incident light angles compared with a Si solar cell and dose not decrease or rather increases under low light conditions. Fujikura is developing new applications of DSC by taking advantages of these properties to the field of "Energy Harvesting" where rapid growth of market has started recently. The results of our outdoor operation tests showed that a DSC generates 1.4 times larger power than a polycrystalline Si solar cell that has the same rated output, when a DSC module is placed on a north wall where the sun light dose not arrive directly. The DSC specially developed for indoor use has twice larger generation performance than amorphous Si solar cells. In this paper we will introduce these technologies of DSC.
Single crystalline materials are special materials whose properties are often emphasized in comparison with those of their polycrystalline materials. They are used in such wide fields as electronic devices, light emittinag elements, optical elements, energy conversion elements, and so on. We are developing single crystalline materials for compound semiconductors and high efficiency optics to realize the next-generation high-performance key devices in the industries.
Yttrium(Y)-based superconducting wires are expected to be applied to various superconducting apparatus. They have high current density and show the high performance in liquid nitrogen, which is much cheaper than liquid helium. In 1991, Fujikura succeeded in developing the key original technology to fabricate Y-based superconducting wire, which was called as ion-beam-assisted deposition (IBAD) method.
An 816.4 m long wire with end-to-end critical current (Ic) of 572 A/cm, corresponding to the world record Ic x L value of 466,981 Am/cm, was achieved at Fujikura. Today, we have established skills of routinely fabricating 500 m long wires with uniform Ic distribution over 500 A. In this report, we introduce recent improved performance of Y-based superconducting wires and developments of key technologies for their applications.
Since the enforcement of the RoHS Directive in July 2006, regulation of environmentally hazardous substances in products has become particularly strict due, for example, to publication of the revised RoHS Directive, tightening of halogen-free policies and the effectuation of REACH regulations. This paper reports on trends in the regulation of environmentally hazardous substances and the status of technical compliance to it.