Multi-wavelength spatial light shaping using generalized phase contrast.

The generalized phase contrast method (GPC) is a versatile tool for efficiently rerouting photon energy into desired spatial distributions. We demonstrate that GPC-based patterned projection shows robustness to shift in wavelength and can maintain the projection length scale and high efficiency over a range [0.75lambda(0);1.5lambda(0)] with lambda(0) as the characteristic design wavelength. The GPC has the capacity to combine multiple wavelengths along the same optical path and to efficiently redirect them into desired distributions such as for array illumination, beam shaping, or grayscale image projection. This opens the possibility for creatively incorporating various multi-wavelength approaches into patterned illumination that can enable new broad-band optical applications.