Abstract: A gradient refractive index (GRIN) lens includes a transparent central disk and transparent annular segments, including central annular segments and peripheral annular segments. The central disk and each annular segment has a continuous optical phase profile at a design wavelength along a radial direction extending outward from a center of the central disk. An optical phase discontinuity is present at the interface between the central disk and the innermost central annular segment and at the interface between each pair of adjacent annular segments. Radial widths of the central annular segments decrease with increasing distance away from the center of the central disk. The peripheral annular segments have optical phase profiles for the design wavelength that are linear or have maximum first derivatives that are constant or become smaller with increasing distance of the peripheral annular segments away from the center of the central disk.

Abstract: A gradient refractive index (GRIN) lens includes a transparent central disk and transparent annular segments, including central annular segments and peripheral annular segments. The central disk and each annular segment has a continuous optical phase profile at a design wavelength along a radial direction extending outward from a center of the central disk. An optical phase discontinuity is present at the interface between the central disk and the innermost central annular segment and at the interface between each pair of adjacent annular segments. Radial widths of the central annular segments decrease with increasing distance away from the center of the central disk. The peripheral annular segments have optical phase profiles for the design wavelength that are linear or have maximum first derivatives that are constant or become smaller with increasing distance of the peripheral annular segments away from the center of the central disk.