Grid-free 3D multiple spot generation with an efficient single-plane FFT-based algorithm.
Algorithms based on the fast Fourier transform (FFT) for the design of spot-generating computer generated holograms (CGHs) typically only make use of a few sample positions in the propagated field. We have developed a new design method that much better utilizes the information-carrying capacity of the sampled propagated field. In this way design tasks which are difficult to accomplish with conventional FFT-based design methods, such as spot positioning at non-sample positions and/or spot positioning in 3D, are solved as easily as any standard design task using a conventional method. The new design method is based on a projection optimization, similar to that in the commonly used Gerchberg-Saxton algorithm, and the vastly improved design freedom comes at virtually no extra computational cost compared to the conventional design. Several different design tasks were demonstrated experimentally with a liquid crystal spatial light modulator, showing highly accurate creation of the desired field distributions.
Engström
David
D
Department of Physics, University of Gothenburg, Göteborg, Sweden.
Frank
Anders
A
Backsten
Jan
J
Goksör
Mattias
M
Bengtsson
Jörgen
J
D000465:Algorithms; D005583:Fourier Analysis; D006696:Holography / Q000379:methods*; D007090:Image Interpretation, Computer-Assisted / Q000379:methods*; D021621:Imaging, Three-Dimensional / Q000379:methods*; D012815:Signal Processing, Computer-Assisted