Tomonori Yazaki

Design and Demonstration of 1Gbit/s Optical Wireless Interface for Mobile Phones

A 1 Gbit/s optical wireless interface for a mobile phone is designed and in particular, the conditions of the diameter of the photodiode and NA of the condenser lens are cleared. A prototype of the instantaneous file transfer system with the interface, which can be attached to a mobile phone, is then fabricated based on the design. The receive-area diameter of 14.3 mm and the receive angle of 31 degrees are experimentally obtained at a transmission distance of 50 mm. 100 MB file transfer between the interfaces attached to the mobile phones is successfully carried out at a transmission distance of 50 mm without a single bit error and in less than 1 second.

1Gbit/s handheld file transfer system with optical wireless interface

We proposed a handheld file transfer system with a 1 Gbit/s optical wireless interface, and demonstrated 1 Gbit/s file transfer at a transmission distance ranging from 20 mm to 100 mm by optimizing parameters

Proposal and demonstration of optical wireless USB 2.0

We propose an optical wireless USB 2.0 system with a 1 Gbit/s optical wireless interface and a new protocol which does not require any change of existing USB peripherals. A wireless video transmission and a data transmission are successfully demonstrated using the proposed system.

Control pulse propagation direction dependence of cross-gain and cross-phase modulation induced in semiconductor optical amplifier

Cross-gain and cross-phase modulation induced in semiconductor optical amplifier depending on the propagation direction of control pulse was investigated numerically and experimentally.

Device length dependency of cross gain modulation and gain recovery time in semiconductor optical amplifier

The cross gain modulation and its recovery time in the SOAs with the various lengths were experimentally investigated. It was found that these values strongly depended on the device length.

Demonstration of optical wireless USB 2.0 system with wireless power transfer

We design and fabricate an optical wireless USB 2.0 system with a wireless power transfer. A coverage of the optical wireless transceiver is expanded by more than 30 % at the optimum distance for the power transfer, which can maximize the coverage of the system with the commercially available power transfer module. Wireless data and power transfer are successfully demonstrated between a portable music/video player and a PC using the fabricated system.

Experimental demonstration of Gbit/s wavelength conversion based on cross gain modulation in cascaded semiconductor optical amplifiers

We experimentally demonstrated 10 Gbit/s XGM based wavelength conversion by using cascaded SOAs adapting intentional loss in-between. The input power dynamic range toward lower level side was increased from 0.8 dB to 1.8 dB by cascading SOAs with the intermediate loss.