An optically coupled sampling system for transient electromagnetic measurements

An optically coupled sampling system (OCSS) for use in free-field transient electromagnetic environments was constructed. The system utilizes fiber-optic data links between a remote sampling head and a mainframe sampling oscilloscope and was designed to operate with a standard 7000-series Tektronix sampling oscilloscope. The primary goal of the research was to demonstrate the feasibility of fabricating a system with a bandwidth on the order of 1 GHz that was also suitable for packaging in scale-model structures. To this end, the remote sampling head can be packaged within a cylindrical shield, excluding power supplies, that measures 18-in length by 2-in diam. A bandwidth of 1 GHz was obtained consistently, with maximum values exceeding 2 GHz. This paper first provides a description of the measurement problem. An overview of the optically coupled sampling system is then presented, followed by a summary of system performance. Recommendations are made for further development.