A photo-electron fusion switch that can perform optical communications without any trouble, even when nodes of a communication source and a communication partner that are large in transmission capacity are connected, and makes it possible to realize a concentrated arrangement of devices having similar functions and reduce the communication processing time is connected to communication source's information processing devices and communication partner's information processing devices and information processing devices that are each different in transmission speed so as to configure an optical network system. The photo-electron fusion switch includes a network processor of an electronic circuit for controlling packet switch functions, a plurality of optical transmitter/receivers that can support coherent communications and has a photoelectric conversion function capable of transmitting and receiving optical signals different in transmission speed, an optical line switching device, and a plurality of multiplexing/separators. Each multiplexing/separator simultaneously transmits and receives respective optical signals different in transmission speed to and from the nodes via optical waveguides.