Includes bibliographical references.The thesis describes the development of a specification for, and prototypes of, an opto-electric voice communications link. The introductory sections deal with the generalised optical communications channel, the available hardware, and some of the research that has been done in the field. The information presented is used to motivate the type of system to be developed. The emphasis is placed on cost, though not as an overriding consideration. Modulation systems are examined, and frequency modulation of an m.f. subcarrier is chosen. The development of the practical system is covered in detail, in particular the receiver frontend circuitry. Considerable discrepancies between the design figures and actual measured performance are analysed, and their causes located. A practical mechanical design is presented, with suggested modifications for production. In conclusion, future developments in the field are examined
