Design and transformation of three dimensional pupils : diffractive and subwavelength

[摘要] Three dimensional pupils are investigated in both diffractive and subwavelength regimes and in various applications to shape the flow of light. In diffractive regime, volume holograms are good candidates for pupils of optical imaging systems thanks to their three--dimensional structure, which provides richer design flexibility compared to conventional two--dimensional pupils. In this thesis, I will propose the system design as well as the optimization of depth selectivity for enhancing the signal--to--noise ratio of ground--based imaging system for the detection of artificial satellites. In addition, deformations of volume hologram pupils promise additional opportunities to design further, more sophisticated point spread functions which are potentially useful for many imaging purposes. Deformations using multiple point indenters will be investigated in terms of both forward and inverse problems. Bulk transformation is a more general approach for pupil design. The physical relationship between transformation and resulting point spread function will be discussed by deriving the corresponding analytical expressions. In subwavelength regime, I will explore the realization of key materials properties including inhomogeneity and anisotropy. Anisotropy can be implemented by elliptical rod lattices; and with anisotropy, cloaking and accommodation of different components of an optical device become possible. Inhomogeneity is discussed in the context of gradient--index media. The additional thin--film wave guidance effect along the third dimension due to fabrication constraints is investigated in detail with the proposal of an all--analytical solution.

[发布机构] Massachusetts Institute of Technology