"ODL (optical data link) modules are one of the basic components used in optical communication systems. When first intoroduced, ODL modules were developed as very simple module applicable for 1 Mb/s transmission. With the progress of optical transmission technologies, ODL modules evolved to become faster, smaller and multifunctional. Today, advanced ODL modules have a transmission rate exceeding 10 Gb/s, a dispersion penalty compensation function, and various control functions for stable transmission using built-in microprocessors. Widely used in applications such as public communication systems, local area networks and mega server systems, ODL plays an important role in the Internet systems and information society. Sumitomo Electric has developed and shipped ODL modules as well as optical fibers and optical devices since 1970s. This paper describes the ODL development concept and technologies of Sumitomo Electric."

Analytical characterization techniques using a transmission electron microscope (TEM) or a focused ion beam (FIB) system have contributed to the development of semiconductor devices. In particular, at Sumitomo Electric, these techniques have been applied to the analysis of metal-InP interfaces and the investigation of ohmic contact formation mechanisms, with the aim of developing Pd based ohmic contacts for p-type InP which has a shallow reaction layer and low contact resistance. For the further reliability and quality improvement of semiconductor products, the author also conducted the development of TEM specimen preparation techniques by using FIB and sampling techniques. As a result, the degradation mechanism of GaAs transistors under high temperature operation and the electrostatic damage (ESD) induced degradation mechanism of InGaAsP LDs were clarified. This paper describes his study on the material development and reliability improvement for semiconductor devices by using characterization techniques.

Large bulk gallium nitride (GaN) single crystal substrates with low dislocation density are the key material for the commercial production of violet lasers. Sumitomo Electric had developed a new process in order to obtain GaN substrate by means of vapor phase epitaxy. A thick GaN crystal layer is grown epitaxially on foreign substrate, followed by separation from the initial substrate, and then, GaN substrate crystal is obtained. However, a large number of crystal defects (dislocations) are generated at the interface of GaN and GaAs due to large mismatch in crystal lattice. Sumitomo Electric also had developed a new method for the dislocation reduction named DEEP (dislocation elimination by the epitaxialgrowth with inverse-pyramidal pits). The thick GaN layer grows with numerous large inverse-pyramidal pits maintained on the surface. As the growth proceeds, dislocations in the GaN crystal are concentrated to the center of the pit. As a result, a wide area with low dislocation density is formed within the pit except the center area. Furthermore, the improvement of the DEEP is described. The position of the pits is fixed at the pre-determined position by means of opposite polarity GaN. Thus, the total number of the dislocations is extremely reduced. This process was named as A-DEEP (advanced-DEEP). GaN substrates based on A-DEEP satisfy all the requirements for the violet laser diode.

Sumitomo Electric Industries, Ltd. is working to develop low-cost and compact reactors, which contribute to the improvement of the converter. We have developed an original tool for reactor electromagnetic/thermal design based on logic equations and Computer Aided Engineering (CAE). In our study, the predicted values calculated using the tool were found to be highly consistent with observed values and the development time of the reactor was successfully shortened. This paper reports the details of our development.

Demand for wireless communications by cellular phones and other wireless communication means is increasing dramatically; data traffic in 2015 is expected to be 10 times that in 2008. To meet such increasing demand, many telecommunication carriers are planning to replace their second-generation systems with third- or future-generation systems. One major problem to be resolved before upgrading the current systems is how to minimize the power increase associated with high data rate and system bandwidth broadening. In such circumstances we have developed a new technology that can dramatically reduce the power consumption of high power amplifiers, which comprise the majority of power consumed at cellular phone base stations. We successfully incorporated this technology into trial products of remote radio heads for base station use. These trial products achieved the industry’s highest level of power efficiency.

To realize Cooperative Driving Safety Support Systems (DSSS) aiming at the reduction of traffic fatalities and serious injuries, an image processing sensor needs to be installed on the road. With such a sensor, automobiles, motorbikes and pedestrians in a driver’s blind corners are spotted, and the obtained traffic data is provided to the driver. For this purpose, the sensor should be able to detect the position and travel speed of objects with a higher precision than that of traffic counters, regardless of weather conditions and time zones. We have developed an image processing algorithm which responds to the demand and enables the reconfiguration of a highly precise detector, even in unknown situations, by adding small amount of training data and computation. In this paper, we report the outline and experimental results of the developed algorithm.

We have successfully developed an XFP (10 Gbit/s small form factor pluggable) optical transceiver module supporting long link distance up to 80 km at 11.1 Gbit/s, which satisfies all of the requirements by XFP multi source agreement (MSA). Power dissipation of the transceiver is less than 3.5 W under extended operating temperature ranging from -5 to +85°C, which is 20% lower than that of the conventional XFP design. Those features are considered to contribute to down-sizing and cost reduction of transmission equipment.

In this paper, we propose a new solution for the optical cable network deployment for a multi-dwelling unit (MDU) by using the Free-Branch Cable. This cable is applicable to the deployment on the floor and the outside wall surface of any scale of MDU and each fiber can be accessed at any point along the span of the cord bundle in order to respond to service order. To test this cabling system, we conducted a field trial at an existing building, and confirmed that the new solution is convenient and effective for the FTTH construction.

We have developed the world highest optical output power infrared light emitting diode (LED) at 940nm. With a newly developed epitaxial layer structure and a p-type electrode, the optical output power was increased to 5.3 mw at 20 mA DC current, which was about 2.5 times higher than that of a conventional 940 nm LEDs. Forward voltage was 1.35V. The full width of half maximum (FWHM) of spectrum wavelength of the device was 25 nm, which is less than half of that of the conventional one. Acceleration testing showed a lifetime of over 10,000 hours with a DC current of 100 mA at 25°C. This new high output power infrared LED is promising as a light source for future applications such as high sensitivity sensors.

A new molten salt system, N-ethyl-N-methyl-pyrrolidinium chloride (EMPyrCl)-ZnCl2, was investigated for the electrodeposition of molybdenum at intermediate temperature. A phase diagram was constructed for the EMPyrCl-ZnCl2 system, which shows the lowest melting point of 45°C at an equimolar composition. A thermal gravimetry indicated that thermal decomposition starts from 230°C for the equimolar melt. The viscosity and conductivity of the equimolar melt were 75 cP and 22 mS cm, respectively, at 150°C. The cathode limit of the equimolar melt was confirmed to be the deposition of metallic zinc by XRD analysis. A smooth metallic molybdenum film was electrodeposited on a nickel substrate by potentiostatic electrolysis at 0.01 V vs. Zn(II)/Zn in an equimolar melt containing MoCl5 (0.9 mol%) and KF (3.0 mol%) at 150°C or MoCl3 (0.2 mol%) and KF (2.0 mol%) at 200°C.

AlGaInP laser diodes (LDs) are used in a wide range of digital equipment, such as MO/CD/DVD optical pick-up units, laser printers and barcode scanners. These lasers are expected to be used for the next-generation hard disk drives (HDDs) using thermally-assisted magnetic recording systems, mobile devices and other digital products. To keep up with the increasing demand, we have undertaken the development of higher-output and lower-power-consumption LDs. By optimizing our 4-inch-wafer process, we have succeeded in the development of a 660 nm short-cavity ridge-waveguide laser (L = 300 μm) that can demonstrate the output power per unit cavity length as high as 100 mW/mm (CW operation, 25°C to 80°C). This output power far surpasses 64 mW/mm by a high-power laser (L = 2200 μm) designed for high-speed recordable DVD systems.

Sumitomo Electric Industries, Ltd. has taken part in the high-temperature superconducting (HTS) cable demonstration project, began in 2007, to verify the reliability and operational stability of HTS cable systems in actual power grids. The company has developed 66-kV-, 200-MVA-class HTS cables, terminations and joints, and built a 30-meter cable system using them to conduct verification tests before the demonstration in Tokyo Electric Power Company’s Asahi Substation in Yokohama. At present, Phase I of the rating validation test has been completed with favorable results, verifying the soundness of the 30-m cable system. A 30-day long-term operation test was also completed successfully. Going forward, Sumitomo Electric will conduct heat cycle and marginal performance tests with the system in Phase II and Phase III.

“SUMIBORON” PCBN tools are widely used in the cutting of hard-to-cut ferrous materials, such as hardened steel, cast iron, and powder metal and contribute to productivity growth and cost reduction for metalworking. In recent automotive industry, powder metal consumption is increasing. The powder metal materials have more flexibility in design and can be sintered into complex shapes. However, these have the disadvantage of poor machinability. Therefore, the demand for PCBN cutting tools for higher precision performance and longer tool life has increased. “SUMIBORON BN7500,” shows a higher precision and longer tool life in the finishing of powder metal parts than conventional PCBN grades by maintaining cutting edge sharpness. BN7500 has the highest cBN content among the present production line and excellent binding force between fine-grained cBN particles. The development and the performance of BN7500 are described in this report.

We have developed a PIN photodiode with a type II quantum well structure, which can operate in the short wavelength region up to 2.5 μm. This photodiode will make uncooled operation possible. The absorption layer consisting of 250 pair-InGaAs(5nm)/ GaAsSb(5nm) quantum well structures was grown on InP substrates by solid source MBE method. The p-n junctions were formed in the absorption layer by the selective diffusion of zinc. Dark current density was 0.92 mA/cm2 , which was smaller than that of a conventional HgCdTe detector. The responsivity at 2.2 μm was 0.6A/W.

Drawing upon the human oculomotor neural system, we developed a vision sensor system with mechanisms to control stereo active cameras and mimic the human vision system such as smooth pursuit (target chasing), saccade (gaze shifting) and the binocular cooperative movements (conjugate and vergence movements). We established a trial machine and conducted a field experiment for simulated passage and crosswalk. In this paper, we describe the process of the system construction along with the results of the field evaluation work.

"Prevention of traffic accidents between human and vehicles on road has become one of the major issues today and the development of advanced in-vehicle safety systems is highly expected. A sensing system installed into a vehicle can be a solution to the issue, playing a complementary role for the elderly with poor detection capabilities, especially in aging society. Although visible light imaging and thermal infrared ray (TIR) sensing have been put into practical use in some fields, yet they fall short of sensing accuracy due to their moisture-absorption property or susceptibility to other heat sources, such as vending machines. Focusing on short wavelength infrared rays (SWIR), the authors have developed the basic technology of sensing and detecting objects by using hyper spectra. This paper presents an overview of the SWIR hyper spectrum sensing method and its evaluation system, along with the experimental results proving the method’s high accuracy in human detection."

Analysis Technology Research Center has contributed to reliable and sophisticated product design and the optimization of manufacturing processes in Sumitomo Electric’s five major business fields through the use of computer-aided engineering (CAE) technology. CAE analysis technology is now increasingly important, since it is the key to developing competitive products. Nevertheless, establishing CAE technology takes a significant amount of time due to the fact that the process from building a mathematical model to experimental validation can take up to several years. In order to shorten this period, we decided to introduce powerful infrastructure including both hardware and software. We devoted our attention to the results of a survey we had conducted to determine the CAE technology requirements of the Sumitomo Electric Group, and investigated the performance of newly developed software in the fields of “structural analysis,” “high-frequency electromagnetic analysis,” “fluid dynamics,” and “molecular design.” Furthermore, we conducted several benchmark tests for large-scale parallel computer systems to select suitable equipment. In this paper, we describe how we settled on our infrastructure building direction and how such an infrastructure system can be utilized effectively in various business fields.