Visual and dynamical measurement of Rayleigh-Benard convection by using fiber-based digital holographic interferometry

We present a method for visual and dynamical measurement of the Rayleigh-Benard convection by using fiber-based digital holographic interferometry. A SM600 fiber with 4μm core diameter is used instead of conventional pinhole, which has better performance to filter out the noises, effectively modify the structure of the optical path and relax the requirement of the laser performance (e.g., coherence length and beam uniformity). The experimental results show the development process of Rayleigh-Benard cell in the container. The corresponding Rayleigh number is 3.6. In the process, the temperature at the top and bottom plates is controlled at 295K and 300K, respectively. The measured temperature distribution and the number of Rayleigh-Benard cell are verified by using simulation and are in good agreement.