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Lossless Projection of Light

J. Glückstad and L. Lading, Optics and Fluid Dynamics Dept., Riso National Laboratory, Roskilde, Denmark, and H. Toyoda and T. Hara, Hamamatsu Photonics K.K. Central Research Laboratory, Hamakita City, Japan.

Imaging of phase objects (i.e., visualizing and projecting the information imprinted by a non-absorbing object into the phase of a transmitted light beam) has always been a subject of considerable interest in optics. From a theoretical point of view, it is a fundamental challenge to devise new phase-only imaging methods that provide the most efficient, simple, and robust use of available photons radiated from a given light source. From an application point of view, a phase-only imaging technique is attractive for at least two reasons. First, the majority of the emitted photons will not be dissipated, preventing heat generation and the resulting damaging effects in the optical hardware. Second, photons that are not absorbed by the optics can be efficiently used and transferred to a desired target projection. Consequently, one can use a weak light source to generate a desired light projection, with strength comparable to that generated by a much stronger light source combined with conventional amplitude modulating optics. On the other hand, one can apply a strong light source in a phase-only modulating system without having to be concerned about deteriorating effects due to absorption.