Apparatus for measuring electrical or magnetic fields by absorption spectrum change

摘要

A fiber optical measuring device for measuring a magnetic or electric field comprises an optical modulator influenced by the field. The optical properties of the modulator are dependent on the magnetic or electric field acting on the modulator. The optical property which is made use of is the field dependence of at least one absorption edge of the radiation absorption spectrum of the modulator material. Optical fibers may be used for feeding light into the modulator and for leading away light that has passed through the modulator.