A phase correction concept is introduced to improve the performance of a spatially multiplexed optic. In a specific example, the optic is a diffractive lens. A phase offset is added to extend the depth of field of the diffractive lens and increase its focusing intensity. This can result in increased signal-to-noise ratio. These diffractive lenses may be used for imaging, focusing, and/or delivering light to an area of interest. They may be used to realize miniaturized medical imaging based on different imaging modalities such as optical coherence tomography, Raman spectroscopy, and fluorescence microscopy. They may also be used for different purposes and applications, for example laser ablation.