Masahito Morimoto

Polymer Optical Waveguide Chip: New Tool for Simple Evaluation of Optical Parameters of Waveguide Elements

A polymer optical chip consisting of 45°-angled cut straight waveguides, Y-splitters, and S-bend waveguides was designed and fabricated to examine a simple evaluation of multimode waveguides. Appropriate input condition was investigated for standardization of an evaluation method of optical characteristics of multimode waveguides.

Co-Propagating Dual-Order Distributed Raman Amplifier Utilizing Incoherent Pumping

We propose a distributed Raman amplifier available for dual-order co-propagating configuration with low-relative intensity noise (RIN) transfer. The first-order and second-order pumps are composed of incoherent and coherent light sources, respectively. By using the incoherent light source as a first-order pump, RIN transfer can be reduced. A semiconductor optical amplifier-based first-order incoherent light source for the configuration has been developed. The results of the RIN measurement and 22.5-Gbaud polarization-division multiplexing 16 quadrature amplitude modulation (PDM-16QAM) transmission experiment over 2720 km in a re-circulating loop show that the proposed configuration will be effective for a practical low-noise co-propagating Raman amplifier.

R=1mm 90°-Bent Multi-Mode Optical Fiber

We investigated the bending losses and the polarization dependent losses of 90° light beam deflection for multi-mode optical fibers (MMF) using small-radius 90°-bent optical fibers with low refractive index UV curable resin.

Bend insensitive small diameter fibers for optical interconnection systems

Bending loss insensitive small diameter fibers for optical interconnection systems using 1100 nm high-speed VCSELs are designed and fabricated. 90°-bending with 1 mm radius is achieved by fabricated 80 μm cladding fibers using stress-free bending technique.

90°-bent with R=1mm optical fiber technique for optical interconnection

In this paper, we report the low loss (<0.06dB single-mode, <0.2dB multi-mode) 90°-bent with 1mm-bending radius optical fiber by using 12-fiber ribbon for optical interconnection systems in both the single-mode and multi-mode case. There are a lot of 90° light deflection techniques based on several types of 45° mirrors.[1]-[6] Our 90° light deflection technique is based on bending optical fiber itself.[7] This technology is easy to be adopted for optical surface mount assemblies that need light beam deflection between the vertical surface-emitting lasers or surface-receiving photodiodes and optical paths parallel to an electric circuit board. We describe the target of our developing system, concepts, difficulty of glass fiber bending by failure probability, a single-mode fiber design for small bending with low bending losses, multi-mode 90°-bent structure using polymer materials and the 80μm-cladding 125μm spacing 12-fiber ribbon for dense packaging and easy handling in narrow spaces. We also describe the 90°-bent connector which has guide-pins splice able with conventional 12MT-connector, a 5Gbit/s×12ch parallel-optical module and these characteristics. Our developing optical interconnection system include the 90°-bent with R=1mm connector and parallel module have good performances for the practical use.

90

In this letter, we demonstrate an extremely low loss (<0.06 dB) 1-mm bending radius 90deg light deflection by using a 12-single-mode-fiber ribbon for optical interconnection systems. This technology is easy to be adopted for optical surface mount assemblies that need light beam deflection between the vertical surface-emitting lasers or surface-receiving photodiodes and optical paths parallel to an electric circuit board. We have chosen single-mode fiber (SMF) for the 90deg-bent fiber expecting the single-mode transmission will be applied for high-performance optical interconnection systems because of its wide bandwidth and stability in transmission characteristics. In order to minimize the bending loss and accomplish a small bending radius, we have developed a new optical fiber having higher refractive index of the core (high delta n fiber) than that of conventional fiber and 80-mum-cladding 125-mum spacing 12-fiber ribbon for dense packaging and easy handling in narrow spaces. It is bent at a radius of 1 mm by heating process with a ceramic heater.

^{\circ}

Polymer optical waveguide devices are getting popular for next generation FTTH application. In order to accelerate the development of polymer optical devices, evaluation of waveguide characteristics should be speeded up. Polymer optical chip containing a combination of 45°-angled cut waveguide, Y-splitter and S-bend structures was designed and fabricated for simple evaluation of multimode waveguides. Input launching such as light source, mode scrambler was investigated for reliable measurement.