We are passionate about light. Light feeds the vision: the “number one” sense that connects us to the world around. A lot of information is carried by light: intensity, space variation (photos…), time variation (communication with light), color and spectral information (spectroscopy, color sensation), polarization (no so well known), phase of the light wave.
Light has infinite number of possibilities for studying material, liquid, gas, surfaces analysis. And when coherent light (perfect sine wave or close to) is used, another world of possibilities is available with interferometry, holography, speckle techniques,… Light has been the key for many revolutions in physics: the connection between light and electricity with Maxwell, the study of light speed with interferometers pushed physics to come to relativity of Einstein, the problem of the black body light emission spectrum (the ultraviolet catastrophe) made Plank to think light in quanta point of view. At this time or a little before, impressionists battled to understand again what is the light and there are still a reference of todays painters and thinkers. Is that enough ? No. Then followed the technology. Lasers, a result of the quantum view of light and of fundamental experiment using microwaves are everywhere and at all prices: communication, data storage, holography, analysis, metrology, CNC machining, energy, medicine, … New light sources come out every day with LEDs, LEDs array, laser diodes arrays etc… And light sensing never stops to evolves since the photodiode with the everyday improving imaging arrays, CCDs, CMOS produced in millions of units. Chemical industry uses extensively light for spectroscopic analysis, laser granulometry for example. Light is versatile, ubiquitous, has no weight, very precise and is easy to produce. Between source and detection new micro mechanical devices doing light control devices like SLM (Spatial Light Modulators), arrays of small mirrors for reflexion or LCD arrays for transmission are appearing at reasonable cost. This will lead us soon to “total light control”: computational control of the phase of the Lightht wave and its intensity at every point of space!