Circuit design for multifrequency square-wave FM control signal/data transmission through optical fiber

Although the multifrequency SWFM data transmission system using an optical fiber has been proposed by Y. Wu et al., no circuit design details have been given. This paper describes the detailed circuit design of key electronic circuits to construct the multifrequency SWFM control data transmission system using an optical fiber for convenience in many applications. The circuit descriptions refer to the multifrequency signal generator; E/O and O/E converters, multifrequency signal decoder, and optical coupler.