| Many optical sensors, including ring laser gyroscopes and interferometric gravitational wave detectors, can be made more sensitive if the index of refraction within the system is carefully tailored. Research into slow light and fast light has, in the last decade, led to methods for controlling the index which have direct applications in sensing. An ideal fast light medium is a transparent material with an anomalous dispersion profile. This same type of material, inserted into an optical resonator, causes the resonance frequency to vary more rapidly with changes in the resonator length than it otherwise would. There is in principle no theoretical limit to the increase in sensitivity; the practical limits are imposed by experimental constraints on our ability to control the index over a broad spectral region.;New experimental and theoretical evidence for the utility of fast light in optical sensing is presented here. |
