Fibre Optics in Metrology
With a carrier frequency of some 1014 Hz, light has the potential of being modulated at much higher frequencies than radio waves. Since the mid-1960s the idea of communication through optical ﬁbres has developed into a vital branch of electro-optics. Great progress has been made and this is now an established technique in many communication systems. From the viewpoint of optical metrology, optical ﬁbres are an attractive alternative for the guiding of light. An even more important reason for studying optical ﬁbres is their potential for making new types of sensors.