Free-space optical bus using cascaded vertical-to-surface transmission electrophotonic devices

A free-space optical bus, which consists of cascaded optical switch devices, is proposed. The switch devices have multiple functions, such as data transmission, data detection, and data repetition. Basic interconnection characteristics were measured with vertical-to-surface transmission electrophotonic devices. Optical switching energy as low as 150 FJ and up to 4 MHz and a relatively high datatransmission rate, i.e., more than 20 MHz, were obtained. Connection cascadability and extendibility were confirmed.