James D. Rees

Some radiometric properties of gradient-index fiber lenses

Some radiometric properties of gradient-index fiber lenses and lens arrays are explored. Consideration is restricted to the paraxial region of fibers that produce erect images at unit magnification. In two instances the radiometric properties of these lenses and lens arrays are considerably different from the properties of conventional (nongradient) lenses. First, the off-axis image plane irradiance for a single gradient-index fiber falls off far more rapidly than the familiar cos(4) law. Second, the exposure (integrated image irradiance) for a fiber array is independent of the object-to-image distance.

Non-Gaussian imaging properties of GRIN fiber lens arrays.

The best focus for a GRIN fiber array is shown to occur when the object and image plane vertex distances are equal, even when neither plane is the proper Gaussian unit magnification plane. This analytical result agrees with previous experimental data. With non-Gaussian imaging, the image plane of best focus for the GRIN array is not coincident with the plane of best focus for the individual gradient-index fibers.

Reduction/enlargement gradient-index lens array

A novel concept of a gradient-index lens array for reduction and enlargement is described. The array is composed of radial gradient-index rod lenses arrayed in a fanlike manner. Design and radiometric equations are presented. Some image aberrations are discussed in a qualitative fashion. The imaging performance and radiometric properties of a sample lens array are given.

Office Applications Of Gradient-Index Optics

The widespread use of arrays of gradient-index rod lenses in the office is described. The important imaging and radiometric characteristics of these arrays are provided along with how these properties change with certain lens parameters. A table of commercially available lens arrays is provided.