DESIGN, TOLERANCING, AND EXPERIMENTAL CHARACTERIZATION OF DYNAMIC FREEFORM OPTICAL SYSTEMS
1 online resource (242 pages) : PDF
University of North Carolina at Charlotte
Although freeform concepts have been considered for many decades, new fabrication capabilities have enabled new classes of optical components and sparked greatly increased interest in freeform optics. Generally defined as surfaces without rotational symmetry, freeform optics enable complex phase variations due to their asymmetry. One approach for freeform optics utilizes multiple freeform surfaces in close proximity. Light transmitted through these surfaces results in a composite wavefront, which is then dynamically changed through controlled relative motions of the freeform surfaces, thereby dynamically changing the overall optical function of the system. These ‘dynamic freeform optics’ offer advantages such as design miniaturization, decreased manufacturing costs, and optical design flexibility. Examples include the varifocal Alvarez lens and a variable diameter Gaussian to flat-top beam shaper. In these cases the output function is varied through relative lateral shifts. The analytical design procedures for these examples have been well documented in previous work. However, previous cases possess inherent design constraints. For example, the classic Alvarez lens has no optical power when the lateral shift is zero, and both examples are limited to rotationally symmetric output functions and lateral shifts along a single axis. A primary objective of this dissertation is to expand design procedures to overcome these constraints for creation of additional novel dynamic freeform optical systems. The optical performance of several example systems is characterized through experimental testing of diamond-machined freeform elements. Furthermore, as the advantages offered by freeform systems are realized, there remain unknowns regarding performance sensitivity to several potential errors such as opto-mechanical alignment, surface form accuracy, and surface finish quality. To this end, this dissertation also includes individual tolerance analyses on each of these error sources, enabling the determination of meaningful tolerance specifications for dynamic freeform optical systems.
FREEFORM OPTICSOPTICAL DESIGNOPTICAL FABRICATIONTOLERANCING
Optical Science & Engineering
Boreman, GlennDavies, MatthewDavies, AngelaAmburgey, James
Thesis (Ph.D.)--University of North Carolina at Charlotte, 2017.
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