An information transmission process is disclosed in which information is transmitted between a signal-emitting port for emitting an optical signal and plural signal-receiving ports through a light transmissive medium in an optical circuit device. The process comprises a first step of transmitting a first information from the signal-emitting port by emitting light in a first emission angle range to transmit first information to at least one of the signal-receiving ports, and a second step, after the first step, of transmitting second information from the signal-emitting port by emitting light in a second emission angle range different from the first emission angle range to transmit second information to at least one of the signal-receiving ports.