High resolution real-time complex modulation using single spatial light modulator

Limited spatial resolution and poor real-time performance are crucial issues in complex modulation. In this paper, a novel and non-iterative scheme for real-time complex modulation with a high spatial resolution is demonstrated. Firstly, the desired complex amplitude field is decomposed into two phase-only masks, which are subsequently displayed side by side on a spatial light modulator. Then, two phase-shift masks at the Fourier transform plane are employed to make beams, modulated by the two phase-only masks, interfering with each other. Finally, an accurate reconstruction of the desired complex amplitude can be achieved theoretically at the output plane. By this method, misalignment tolerance of the proposed scheme is effectively enhanced, which significantly decreases the difficulty of realization. Besides, this method is quite simple and requires only a little commonly used optical elements. Consequently, the whole modulation procedure can be fast and easy to implement. Simulation results verified the validity of our proposed method. It may be a promising means for numerous optical applications, such as holography. (letter)