Hidenobu Hirota

Athermal arrayed-waveguide grating multi/demultiplexers composed of TiO/sub 2/--SiO/sub 2/ waveguides on Si

We have successfully demonstrated a novel athermal arrayed-waveguide grating (AWG), which is composed of highly TiO/sub 2/-doped SiO/sub 2/ glass rib waveguides on a silicon substrate. We found that the wavelength temperature coefficients of the athermal AWG depend not only on the TiO/sub 2/ concentration but also on the annealing temperature after fabrication. We obtained a center wavelength temperature coefficient of 0.7 pm//spl deg/C at a TiO/sub 2/ concentration of 66 mol% and an annealing temperature of 900/spl deg/C.

Four-degree hub switch module using multi-chip planar lightwave circuit integration technology for transparent ROADM ring interconnection

We have developed a PLC-based 32-wavelength 4-degree hub switch module, which consists of a broadcast coupler with a demultiplexer for local-drop, and a WSS with wavelength specific ports for local-add. The module size is 220/spl times/135/spl times/14 mm. The insertion loss of the express path in the WSS is 10.8 dB.

High-efficiency light injection and extraction using fiber bending

We achieve a temporary optical coupler that injects/extracts light into/from a fiber with high efficiency by using fiber bending. We demonstrate experimentally that extraction efficiency is improved by using a double-clad fiber.

Stripping-free physical contact optical connector

We propose a new stripping-free optical connector that enables us to realize physical contact (PC) connection and facilitate assembly, and demonstrate PC connection with a low average connection loss of 0.16 dB.