High power 4G optics (Conference Presentation)

The optical power of diffractive waveplate structures is limited not as much by fabrication technology issues as by the fundamental features of light propagation in complex anisotropic structures. The infinitely thin two-dimensional film approximation does not apply, and the efficiency of 4G lenses, prisms, etc., is reduced for geometries corresponding to sharp focusing lenses and large diffraction angles. Due to thin-film nature, these films can be combined to reduce effective focal length, increase effective diffraction angle, topological charge, etc. Along with this, we will discuss the opportunity of increasing optical power of 4G lenses, prisms, etc. without compromising efficiency.