Probing local displacements on a scattering surface can be achieved using an adaptive interferometer. Photorefractive-crystal based interferometer are popular, but alternatives exist, such as Adaptive Gain interferometer. Such setups take advantage of the non linear phenomena in laser media. Because of the gain saturation, it is possible to write a gain hologram and a refractive index hologram to achieve an adaptive interferometer with a linear response. In addition, laser media based setups have a fast response time (≤ 100 µs), which makes them interesting for application such as detection of photoacoustic waves in living biological samples.