Kotaro Saito

Side-view based angle alignment technique for multi-core fiber

Precise rotational angle alignment to splice multi-core fiber is successfully achieved by analyzing the symmetricity of side view contrast. Our proposed technique potentially enables the automatic passive low loss fusion splicing of multi-core fiber.

Mechanical Splice Characteristics of a Hole-Assisted Fiber

The mechanical splice characteristics of a single-mode hole-assisted fiber (SM-HAF) are investigated both numerically and experimentally. Mode-coupling theory is used to investigate the mechanical splice loss characteristic of the HAF. We introduced an air filling fraction and a \bm V-parameter to allow us to consider an HAF with arbitrary structural parameters. We derive the optimum conditions (e.g., refractive index and temperature coefficient) of a solid-type refractive index matching material to realize good splice and return loss characteristics simultaneously. The validity of the derived conditions is investigated experimentally. Finally, we confirm that we can achieve comparable splice characteristics to those of conventional single-mode fiber splices by using the optimized refractive index matching material independent of the structural parameters of the SM-HAF.

Multi-core fiber based pluggable add/drop link using rotational connector

We realize an arbitrary core access in multi-core fiber (MCF) by using a planar lightwave circuit and a rotational connector technologies. This enables easy and reconfigurable construction of a high-speed multiple link over an MCF.

Design of 125 μm cladding multi-core fiber with full-band compatibility to conventional single-mode fiber

We realize a multi-core fiber (MCF) fully compatible with conventional single-mode fiber (SMF) in all telecommunication bands while maintaining 125 μm cladding. The designed MCF enables us to construct a full-band SDM transmission link harmonizing with existing SMF links.

Field Assembly Splice Technique With Solid Refractive Index Matching Material

Solid refractive index matching material enables us to splice fiber with air holes as well as conventional single-mode fiber. In this paper, we report our study of the applicability of solid refractive index matching material to a field assembly splice technique. We investigate pressing force and bending loss characteristics as a function of fiber buckling experimentally. We also investigate the impact of the hardness of the solid material on the splice loss characteristics of the field assembly splice technique. Then we derive appropriate splice conditions for both the hardness of the solid material and fiber buckling. Finally, we confirm the validity of the derived splice condition by using a single-mode hole assisted fiber.

Multi-Core Fiber Technology: Next Generation Optical Communication Strategy

Space-division multiplexing is expected to be a key technology both for dealing with the future capacity crunch facing traditional single- mode fiber and for realizing a sustainable optical network that can accommodate the various data streams originating from, for example, future 5G communication, the Internet of Things, and machine-to-machine networks. This article describes the potential of space-division multiplexing as regards optical fiber and cable technology. We focus on the potential of multi-core fiber and investigate the reality of multi-core-fiberbased space-division multiplexing optical wiring as the first example of a space-division multiplexing application taking the latest research and development into consideration. Finally, we show that the key technology behind multi-core-fiber-based space-division multiplexing optical wiring is ready for discussion as a near future standard.

Space division multiplexing technology: Next generation optical communication strategy

Space division multiplexing (SDM) is expected to be a key technology both for dealing with the future capacity crunch facing traditional single-mode fibre (SMF) and for realizing a sustainable optical network that can accommodate the various data streams originating from, for example, future 5G communication, the Internet of things (IoT), and machine to machine (M2M) networks. This paper describes the potential of SDM as regards optical fibre and cable technology. We focus on the potential of multi-core fibre (MCF), and investigate the reality of MCF based SDM optical wiring as the first example of an SDM application taking the latest research and development into consideration. Finally, we show that MCF based SDM optical fibre cable will be a promising technology for next generation optical networks, and the key technology behind MCF based SDM optical wiring is ready for discussion as the near future standard.

Holey fibers for low bend loss

Abstract Bending-loss insensitive fiber (BIF) has proved an essential medium for constructing the current fiber to the home (FTTH) network. By contrast, the progress that has been made on holey fiber (HF) technologies provides us with novel possibilities including non-telecom applications. In this paper, we review recent progress on hole-assisted type BIF. A simple design consideration is overviewed. We then describe some of the properties of HAF including its mechanical reliability. Finally, we introduce some applications of HAF including to high power transmission. We show that HAF with a low bending loss has the potential for use in various future optical technologies as well as in the optical communication network.

Design of Thin Cladding BIF Using Cutoff Wavelength Shortening Effect

We experimentally investigate the cutoff wavelength shortening effect that occurs when the cladding diameter is reduced. The influence of coating thickness, and thus, cladding diameter, on the transmission loss is also discussed. We derive an empirical model of cutoff wavelength and transmission loss as a function of the cladding diameter and coating thickness. The empirical model reveals that a further reduction in the cladding diameter of step index type bending-loss insensitive fiber (BIF) is possible. The validity of the proposed BIF design is confirmed using a 70-μm cladding diameter BIF and jumper cords. This BIF enables us to construct optical fiber networks with higher reliability.