Design of radial gradient-index lenses for dual-band visible to short-wave infrared imaging systems

Abstract

Over 100 doublets were designed using a polychromatic gradient-index (GRIN) design model to analyze the benefits of radial GRIN profiles in broadband visible to short-wave infrared (vis-SWIR) imaging system applications. The polychromatic GRIN design model can be applied to any GRIN material, but for this work, titania silicate glass was investigated. A multielement design study with Petzval lenses was performed to show improved color correction when using GRIN elements. Results from the doublet and Petzval designs illustrate that in broadband vis-SWIR imaging applications, GRIN can either improve system performance or reduce a cemented homogeneous doublet to a GRIN singlet.

Broadband high-resolution gradient-index micro-objectives for optical biopsy systems

“…smaller slope), corresponds to better UIŝ econdary color correction. The same principle is true for a triplet, where the degree of color correction is proportional to the area of the triangle connecting the three materials on the map 6,10 . Each material in the fiveelement homogenous and four-element GRIN designs is plotted on the Abbe number vs. partial dispersion map in Figure 6.…”

“…In a standard doublet, the degree of primary color correction relates to the separation between the Abbe numbers of the two materials 6,10 . A larger separation between Abbe numbers corresponds to better primary color correction.…”

“…A larger separation between Abbe numbers corresponds to better primary color correction. The degree of secondary color correction relates to the slope of the line connecting the two materials on an Abbe number vs. partial dispersion map 6,10 . Therefore, closer partial dispersion values (i.e.…”

“…The primary benefit of radial gradient-index (GRIN) elements in imaging applications is the additional degree of freedom introduced with a radial gradient's optical power. With the use of a titania silicate GRIN glass 5,6 , achromatization can be achieved with a single element thus cementing two or more homogeneous materials together can be avoided.…”

Mapping of index of refraction profile for polymer gradient index optics using confocal Raman spectroscopy

“…2 Periodic focusing and collimation within a single radial GRIN lens give it a variety of cited applications in fiber communications, 3,4 biomedical sensing, 5,6 and imaging. 7,8 For most common GRIN rods with radial symmetry, the index of refraction changes only as a function of radial distance from a linear axis. One common way of making a glass radial GRIN lens is by ion diffusion 7,8 through the boundaries of a glass rod.…”