Measuring three-dimensional temperature field by digital holographic interferometry

The feasibility of measuring the three-dimensional temperature distribution and its changing by digital (viz electronic) holographic interferometry is investigated. An experimental setup is designed to record the optical hologram of a temperature field directly by a CCD (charge coupling device) array with small size. By means of fast Fourier transform and spectrum filtering of the recorded holograms, the temperature distribution around the head of an electric iron is obtained. It is shown from the experimental results, that the digital holographic interferometry may be a novel holographic interferometry with high speed and promising applications by using high revolution CCD array and modern computer. It can be used to observe and measure the dynamic change of a three-dimensional object field in real time. Meanwhile, the number of the interference fringes can be multiplied by the principle of phase multiplication, or the phase different between two arbitrary points in the field can be directly calculated, so that the measuring precision can be greatly improved.