  Double-pulsed holographic interferometry with photorefractive crystalsGeorges, Marc  ; Thizy, Cédric ; Lemaire, Philippe et alin Zhang, G.; Kip, D.; Nolte, D. (Eds.) et al Photorefractive Effects, Materials, and Devices (2005, July) We present the achievement of the European PHIFE project (pulsed holographic interferometer for the analysis of fast events) and which consisted in the development of holographic head principles connected ... [more ▼] We present the achievement of the European PHIFE project (pulsed holographic interferometer for the analysis of fast events) and which consisted in the development of holographic head principles connected to a YAG Q-switch double pulsed laser. An industrial prototype has been built with the aim of Hill-field out-of-plane displacement measurement at a high repetition rate. In parallel, a new double pulse laser with 25 Hz repetition rate, high energy (800 mJ/pulse in single pulse operation), variable delay between pulses (from 1 to 200 mu s) and based on a single cavity is studied [less ▲] Detailed reference viewed: 20 (1 ULg) Double-pulsed holographic interferometry with photorefractive crystalsGeorges, Marc ; Thizy, Cédric ; Lemaire, Philippe et alConference (2005, June) Detailed reference viewed: 3 (0 ULg)Dynamic holographic interferometry with photorefractive crystals : review of applications and advanced techniquesGeorges, Marc ; Thizy, Cédric ; et alin Gastinger, K.; Lokberg, O.; Winther, S. (Eds.) Speckle Metrology 2003 (2003, June) We will present the basic properties of photorefractive crystals and show how they can be used efficiently in holographic interferometry experiments. We then will present some holographic systems and ... [more ▼] We will present the basic properties of photorefractive crystals and show how they can be used efficiently in holographic interferometry experiments. We then will present some holographic systems and their numerous applications. With continuous illumination, we will show classical non destructive testing (defect detection), displacement metrology, vibration mode shape visualization, as well as a study for the use of photorefractive crystals in microgravity monitoring of fluid (FSL experiment aboard the International Space Station). With pulsed illumination we will present the possibilities of the photorefractive crystals in vibration measurement (and will introduce the ongoing EC-funded PHIFE research project). The purpose of the paper is to unmystify photorefractive crystals and to show that they could be a good alternative to traditional speckle-based techniques for highly demanding applications. For that we will highlight the highest resolution achieved as well as the high temporal dynamics of the holographic recording [less ▲] Detailed reference viewed: 7 (0 ULg)Holographic interferometry with a 90 degrees photorefractive crystal geometryGeorges, Marc ; ; et alin Delaye, Ph; Denz, C.; Mager, L. (Eds.) Photorefractive Effects, Materials, and Devices (2003, June) Holographic interferometers are generally designed in the common geometry where both interfering waves (reference and object) enter the crystal by the same window (co-propagating configuration). The ... [more ▼] Holographic interferometers are generally designed in the common geometry where both interfering waves (reference and object) enter the crystal by the same window (co-propagating configuration). The alternative presented here consists in using a reference beam entering the crystal by a lateral face. The crystal has to be cut adequately in order to obtain electro-optic properties similar to that of the co-propagating configuration but with a smaller optical scattering noise. Therefore higher signal-to-noise ratios are expected in the interferograms. We will present the main features and constraints of this configuration together with the experimental study of its noise characteristics. This work has been performed for sillenite and semiconductor crystals [less ▲] Detailed reference viewed: 7 (1 ULg) |
||
