| The first objective of this thesis is to design, fabricate and characterize Radial Angular Filter Arrays (RAFAs). The motivation is to replace bulky and slower goniometer-based instruments or complicated interferometric systems to achieve low-cost, real-time and simplified optical scattering measurement. In addition, RAFAs are designed to support angle-resolved spectroscopic analysis for structural characterization, bio-sensing, and material identification. RAFAs originate from Angular Filter Array (AFA) in Angular Domain Imaging (ADI). They consist of radially-distributed micro-machined channels in a silicon substrate. Each channel collects photons emitted from the focal point at a specific angle and only passes through photons traveling within a small acceptance angle of the channel direction. This angular filtering function is independent of photon wavelength in the visible and near infrared range. A RAFA provides a means to obtain both angular and spectral information of scattered light in a single exposure. The primary contribution of this thesis project in this field is to develop a RAFA from a concept to a fully functioning device, which expands the applications of AFA beyond biomedical imaging and facilitates the applications of angular spectroscopy. A novel optical characterization system based on both Nano Hole Arrays and RAFAs for potential Surface Plasmon Resonance sensing applications is proposed and tested.;The second objective of this thesis is to advance the angular domain spectroscopic analysis in the biomedical imaging field by applying the multi-spectral analysis to reflectance ADI setups other than the conventional transillumination systems. This new technique allows non-invasive in vivo angular domain spectroscopic imaging samples too thick to perform transillumination. The contribution in this field is to add spectroscopy to the existing Deep-Illumination ADI system. A series of improvements in setup and image processing are practiced to enable Deep-Illumination Angular Domain Spectroscopic Imaging (DI-ADSI) for tissue-mimicking phantoms. The results obtained demonstrate that its depth penetration, field of view and spatial resolution are between micro-reflectance-imaging technologies such as Optical Coherent Tomography and Confocal Microscopy, and macro-reflectance-imaging technologies such as Diffuse Optical Tomography, satisfying the value-proposition of DI-ADSI. It suggests that DI-ADSI has the potential for low-cost and fast in vivo tissue scanning for superficial targets.;Keywords: Radial Angular Filter Array; Angular Spectroscopy; Optical Scattering; Angular Domain Imaging; Angular Domain Spectroscopic Imaging. |
