Vector Aberration Theory With Application To Off Axis Head Mounted Display Design

A brief study of vector aberration theory and its application in the off-axis head mounted display design is presented in this dissertation. As a direct extension of rotationally symmetrical wave aberration theory, the vector aberration theory requires only the new concept of aberration field nodes. It is pointed out that this theory is very effective in the aberration analyses of optical systems with tilt and decenter, can help the optical designer understand the change of aberration fields and give useful design insights for the optical system without rotationally symmetry.Reviewing the traditional wave aberration theory, the third-order optical aberrations of near-circular pupil optical systems without symmetry are described in the Section Two. The nodal field behavior with specific-aberration -characteristic symmetry is summarized. It is pointed out that this theory is not restricted to small perturbations and useful in the reflective, refractive and hybrid refractive-reflective optical systems.A real-ray-based method for locating individual spherical surface or aspheric cap portion aberration field centers is developed in Section Three. Within the optical design software CODE-V, macros are complied to analyze the third-order aberrations for optical systems with small tilt or decenter. Through three different and simple optical systems, the results obtained with the macros are identical with these got in optical design software, which demonstrates their correction and effectiveness. Using the vector aberration theory, the misalignment induced aberrations of Ritchey-Chretien telescope is analyzed in Section Four. And then they are simulated in the optical design software; the effects of alignment perturbation on the aberration fields are summarized; the misalignment is calculated based on the location of the nodes of aberration fields; the effects of the astigmatic figure error of the primary mirror on the aberration fields are also developed. It is shown that vector aberration theory can provide important insights that are significant for the development of effective alignment techniques and also for the analysis and optimization of the optical system with small perturbations.Based on the direct Zernike coefficients optimization, an off-axis helmet-mounted display with small field of view is designed in Section Five, which shows the effectiveness of the vector aberration theory during the design and optimization process of the off-axis optical systems with large tilts and decenters. A more computationally tractable model of the kinoform lenses in hybrid refractive-diffractive systems is proposed by taking into consideration the actual phase function of the kinoform lenses for every wavelength. The principle and outline of this modified model are explained. And the results of this approach are compared with the more conventional single order calculation and with the standard diffraction-order expansion by using a practical hybrid optical system example.Finally, Section Six summarizes the works and indicates the areas where this work may be continued.