OPTICAL COMMUNICATION SYSTEM FOR DRILL HOLE LOGGING

摘要

An optical communication system for drill hole logging comprises an armoured cable 58a containing one or more optical glass fibres 23a and 28 inside a tubular moisture barrier, a neodymium laser 21a capable of radiating infrared light into at least one of the glass fibres, a modulator 31 in a downhole cable-head connector shell 10a for modulating light and returning it to the surface, and a semiconductor detector 34a for demodulating the data signal from the returning light.