Optical power for sensor interfaces

Abstract

Hybrid optical fibre sensors in which conventional electrical sensors are used in conjunction with optical fibre data transmission are somewhat simpler to realize than the all optical sensor. Power for such sensors can be supplied optically, but a single photodiode, while it is convenient to interface to an optical fibre, cannot produce a voltage high enough for active interface circuitry. The author considers methods of stepping the voltage up to a usable value, and how their performance may be optimized. An example is given of a platinum resistance thermometer interface that is optically powered.