Sub-nanometer to millimeter vibration detection by dynamic holography

The possibility to record a dynamic hologram allows the design of a new generation of optical sensors insensitive to the surface state of the inspected target. The response time of the holographic media governs the performances with a range going from sub-nanometer displacements for ultrasonic vibrations to millimeter displacements for acoustic vibrations. We present a new generation of optical vibration sensors that uses dynamic holography in photorefractive materials to detect sub-nanometer to millimeter transient displacements of rough surfaces.