Optical Coupling Scheme Research Articles

Optically-Coupled Floating Double Probe for Local Electric Field Measurements in Pinch Discharge Plasmas

Local electric field signals from a floating double probe immersed in a pinch discharge plasma are transmitted via a pair of fiber optic cables in order to achieve electrical insulation between the probe circuit and an oscilloscope. This optical coupling scheme has a higher electrical insulation voltage and a wider frequency response than the commonly-used isolation transformer methods and commercially-available photocoupler devices. The measuring system consists of a transmitter with light-emitting diodes and a receiver with PIN diodes and responds in the frequency range up to 3 MHz. Transient noise, which disturbs the probe measurements in the implosion phases of pinch discharges, has been eliminated.