Passive introduction of carrier fringes in real-time photorefractive interferometers for single interferogram analysis

We propose a new technique to introduce carrier fringes in an holographic interferometric set-up for deformation or vibration analyses. This technique makes use of the anisotropic diffraction processes of photorefractive crystals. The main advantage of the proposed technique is that it just involves static components, no moving parts or active components are required. This technique is demonstrated in a real-time interferometric set-up operating at the wavelength of 1.06 μm and with a GaAs photorefractive crystal as the holographic medium.