Fujikura Technical Review

As network traffic increases, optical cables for connecting buildings in data center require more economical and efficient cable installation method, such as air-blown installation. We have successfully developed the 288-fiber Indoor-Outdoor Air Blown Optical Cable with two different flame-retardant grades for Europe and North America. Since this cable is applicable to both indoor and outdoor environments, this cable covers both indoor and outdoor areas by a piece of this cable. This cable complies with ICEA S-122-744 for mechanical characteristics and ICEA S-104-696 for environmental characteristics, having over 1000 Ft jetting characteristics.

In recent years, the application of multi-fiber optical connectors has been expanding rapidly. In particular, some data center operators apply cutting-edge technologies such as AI and ML (machine learning) to their servers for increasing the speed and capacity of data transmission, and the number of connection points is expected to increase exponentially. There are problems for the limitation of server rack space to accommodate high-density connection and the control of connection loss. As a solution to these issues, Fujikura and US Conec have jointly developed a group of MMC connectors with ultra-compactness and low loss. The developed products have optical characteristics comparable to those of current MPO connector and have been evaluated in various performance tests which has been confirmed and maintain excellent optical performance.

In this paper, we present a millimeter-wave-band power amplifier (PA) for the 5th generation of mobile technology (5G) base stations. The PA adopts an output matching network with integrated transmission/reception switches to support time-division duplexing, while being designed to maximize the saturated output power (Psat) and power-added efficiency (PAE) and higher linearity (i.e. lower AM-AM distortion) in the n257, n258, and n261 frequency bands specified by the 5G NR. The PA fabricated in a 130-nm SiGe BiCMOS process demonstrates a maximum gain of 30.3 dB and a 3-dB bandwidth of 9.8 GHz, and it achieves a Psat over 20 dBm, a PAE of over 22%, and an AM-AM distortion of less than 0.1 dB in the 24–30 GHz range. The figure of merit of International Technology Roadmap for Semiconductors (ITRS FoM) calculated from these parameters reaches competitive value of 93.3. Furthermore, in modulation signal measurements, the PA demonstrates an output power of 12.3 dBm, a PAE of 8.8%, and an adjacent channel power ratio of -32.7 dBc when the error vector magnitude is -25 dB (5.6%).

The 60 GHz band has wide frequency channels, making it suitable for high-speed, large-capacity communications. It is expected to be applied in areas such as high-definition and low-latency video transmission. To help users assess the applicability of 60 GHz band wireless communications, this paper presents the results of transmission characteristics evaluations conducted in actual outdoor environments. The evaluations were carried out using 60 GHz band millimeter-wave wireless communication modules developed by Fujikura, which have obtained technical compliance certification.

Inductively coupled plasma mass spectrometer(ICP-MS) is an elemental analyzer with high sensitivity and high selectivity, and is one of the analytical instruments used in the industrial field. Recently, new analysis methods that connect laser ablation or high-performance liquid chromatograph with ICP-MS have been attracting attention. This paper provides an overview of ICP-MS analysis and introduces various ICP-MS analysis examples in the industrial field.

In recent years, AI technology has made remarkable advancements and has been increasingly utilized in various sectors of society. As a result, expectations for the application of AI technology in the manufacturing industry have also grown. Our company has been actively pursuing the implementation of AI technology using deep learning since 2015, and we have achieved successful integration in inspection processes, among other areas. This paper aims to describe a case study where AI technology was introduced in the field of device control, expanding the scope of its application.

Fiber laser is becoming more popular in the processing field. In recent years, expectations for single mode fiber lasers with both high output and high beam quality have increased due to the possibility such as the expansion of processing targets and the energy transmission field. So far, we reported a single-mode fiber laser with an output of 8kW. In this report, aiming for even higher output, we realized a 10kW single-mode fiber laser with suppression of stimulated Raman scattering (SRS), high efficient and high beam quality.

Fiber Bragg grating (FBG), which is written in the core of an optical fiber using ultraviolet laser light, has attracted considerable attention in the field of optical fiber sensing. We developed optical fibers that enable writing gratings through a coating, and applied the writing method to produce a long-gauge FBG array that is suitable for distributed sensing. Sufficiently high reflection signal level without ghost signal was obtained by stepwise changing the wavelength of each unit FBG. Furthermore, the high precision laser scanning position and fiber feed mechanism enable stable FBG connection with small gaps.

In today fs highly information-oriented society, the workload of data processing is dramatically increasing. We investigate Optical Neural Network (ONN) as a potential technology for higher-speed processors with lower energy consumption. In this report, we developed a novel ONN processor that expedites quick switching of input and processing by using a unique configuration with a liquid crystal light modulator. The capability of the processor was shown by achieving high classification accuracy on the MNIST dataset.