One-mega frame-per-second phase-shifting digital holography

The authors present high-speed motion pictures of phase-image obtained by digital holography. To obtain only the complex amplitudes of dynamically moving objects free from unwanted images such as non-diffraction wave and the conjugate image in digital holography, parallel phase-shifting interferometry was applied. High-speed motion picture of phase image of the dynamic change of air induced by focused femtosecond light pulse was demonstrated at the rate of 262,500 fps. Also, motion pictures of phase image of high-speed air breakdown induced by the spark discharge between two electrodes at the rate of one-mega frames-per second have been achieved. This speed is the fastest not only phase-shifting digital holography but also all of digital holography.