Atsushi Sugitatsu

43 Gbit/s EAM-LD module with built-in driver IC employing novel cathode-floating bias circuit

A novel design of cathode-floating bias circuit realizes 43 Gbit/s EAM-LD module with mask margin of 16%, and cooler power consumption of 0.5 W.

Mechanical optical switch using flexible polymeric waveguide

We have proposed the novel optical switch using the polymeric waveguide, which is expected to have several advantages, such as low insertion loss, high reliability, and low cost. The polymeric mechanical switch (POMS) takes advantage of flexibility of the polymeric waveguide, and switching operation is achieved controlling physical contact between the cores at the crosspoint. The excess transmission loss of 0.1 dB/crosspoint and the excess reflection loss of 1.9 dB/crosspoint are achieved. Also the switching time of less than 300 /spl mu/s is successfully demonstrated. The total loss values of 2.4 and 10.2 dB are expected for shortest and longest paths within the 32/spl times/32 port count POMS, respectively.

High Coupling Efficiency Optical Triplexer Module for 10G-EPON OLT Transceiver

The optical triplexer module, which consists of a 10.3-Gb/s transmitter [electroabsorption modulator integrated laser diode (EA-LD)], a 1.25-Gb/s transmitter (distributed feedback (DFB)-LD), and a 10.3-Gb/s/1.25-Gb/s dual-rate receiver [avalanche photodiode (APD)], has been developed for 10-Gb Ethernet passive optical network (10G-EPON) optical line terminal (OLT) transceiver. We have adopted a newly developed three lens optical system to accomplish high coupling efficiencies of two LDs as -2.84 and -1.65 dB. Moreover, we have adopted dual-rate preamp IC and high responsivity APD more than 0.78 A/W, and realized high receiver sensitivity of - 30.7 dBm for 10.3 Gb/s and - 35.7 dBm for 1.25 Gb/s. The triplexer module fully accomplishes IEEE802.3av PR30 standard specification with fair margin in a small package.

Polymeric Waveguide Optical Switch With Bascule Structure Using Novel Trench Forming Process

We develop a polymeric waveguide optical switch with a bascule structure. Our novel matrix switch diverts light from one waveguide to a crossing waveguide in a polymeric waveguide film, using total internal reflection (TIR) of the interface between a waveguide and a trench at the waveguide cross point by mechanical actuation. The key technique for achieving a low-loss property is a novel cleaving method of forming trenches at waveguide cross points. We achieved a loss of 5 dB for the longest path of an 8 times 8 matrix switch demonstrator, high speed switching operation up to 100 mus, and reliable performance over 10 million times switching.

Wavelength stabilized 980 nm pump laser suitable for uncooled application in metro networks

Wavelength of 980nm pump lasers are stabilized not only with fiber-Bragg-grating but also without it over wide range of temperature. These are suitable for uncooled fiber amplifier application in metro networks.