Abstract

This chapter provides an introduction to the notion of measuring physical properties with light. Measurements exploit the wave nature of light where the properties of wave amplitude, polarization, frequency, and phase are connected to the property to be measured. A measurement begins with the detection of the energy delivered by the light field. The measured energy is then connected to the measurand, that is, the physical property or parameter to be measured, by understanding the way in which the light has interacted with the environment and the way in which the environment changes the wave properties.