Abstract
To realize practical optical communication through human body, an experimental study was conducted using the near-infrared light through a human hand. A wrist-watch type light transmitter was made and the possibility of the optical signal transmission from the wrist to the fingertip was confirmed. A practical light receiver was installed in a door-knob. Fig.1 shows a wearable light transmitter and a door-knob type receiver. The feasibility of the optical data transmission through the adult hand was verified. The optical radiation from the hand was found to be confined in close proximity (within 100 mm range) of the hand. This controllability of radiation guarantees high security in practice.
