Shinya Iwasaki

Dependence of exciton transition energy of single-walled carbon nanotubes on surrounding dielectric materials

Abstract We theoretically investigate the environmental effect for optical transition energies of single-walled carbon nanotubes (SWNTs), by calculating the exciton transition energies of SWNTs. The static dielectric constants used in the exciton calculation can be expressed as a function of the dielectric constants of the surrounding material and that of the SWNT, in which the static and dynamic dielectric constants of the SWNT represent the screening effect of core electrons and the valence π electrons, respectively. The calculated results reproduce the environmental effect of the experimental transition energies for various surrounding materials and for various diameters of SWNTs.

Visible light road-to-vehicle communication using high-speed camera

We have been proposing visible light road-to-vehicle communication at intersection, using LED traffic light as the transmitter and on-vehicle high-speed camera as the receiver. Visible light communication is a wireless communication method using luminance, transmitting data by emitting light. Thus when we use image sensor as the receiver, detection of the transmitter is required to enable the communication. In this paper, we propose transmitter detection algorithm supposed that the sequence is captured at 1000 fps. We also made experiments to verify our algorithm, using the sequence captured by a high-speed camera fixed on a vehicle which is running at 30 km/h.

A New Receiving System of Visible Light Communication for ITS

This paper discusses a new receiving system for visible light communication applied to intelligent transport systems (ITS). We use a light emitting diode (LED) traffic signal as a transmitter that sends information to vehicles that feature a receiver. There are, however, several problems associated with applying visible light communication to the field of ITS. First, we have to transmit information over long distances; second, the relationship between the transmitter and the receiver position changes with time; and third, the communication is affected by a lot of optical noise. Here, we propose a new receiving system to solve these problems and construct a prototype. Evaluation experiments on the system demonstrate its validity.

Basic Experiments on Paralle Wireless Optical Communication for ITS

In this paper, we propose parallel wireless optical communication with an LED traffic light as a transmitter and a high-speed camera as a receiver. Today, it is proposed to use visible light communication for road-to-vehicle communication, which assists drivers by providing various information. It is also proposed to use LED traffic light as its transmitter. Thus in this paper, we propose a road-to-vehicle communication system using a high-speed camera. In our proposing system, we receive data by capturing the transmitter with the high-speed camera, making it possible to recognize each LED separately. We have examined communication speed and conducted experiment of parallel data transmission under laboratory condition.