UCLA

Imaging systems capture light rays contain rich information, which can be described by the plenoptic function, ?(?, ?, ?, ?, ?, ?, ?)—where ?, ?, ? represent spatial coordinates; ?, ? denote emittance angles; ? signifies wavelength; and ? denotes time. Given a finite photon budget, it is crucial for an imaging system to maximize the information yield from each captured image. Yet, traditional cameras only capture two-dimensional spatial data (?, ?), neglecting the wealth of information. Capturing multi-dimensional information presents significant challenges, primarily due to the complexity of mapping high-dimensional datacubes onto a two-dimensional detector array. This mapping process introduces a fundamental trade-off among various axes of information, such as spatial, angular, and spectral dimensions, which can adversely affect imaging speed, resolution, and other critical parameters. Balancing of these factors often leads to compromises in one aspect to enhance another, pose a significant challenge in designing and implementing a multi-dimensional imaging system. In response to these challenges, this dissertation presents three innovative multi-dimensional optical imaging systems. The first system, snapshot hyperspectral light field imaging utilizing image mapping spectrometer (LF-IMS), represents a five-dimensional (?, ?, ?, ?, ?) imaging system. It is uniquely designed to maintain full light throughput, enabling the capture of detailed three-dimensional spatial and spectral information without sacrificing efficiency. The second system, snapshot hyperspectral light field tomography (Hyper-LIFT), leverages compressed sensing to facilitate five-dimensional (?, ?, ?, ?, ?) imaging. This approach significantly alleviates the tradeoff between different dimensions of information, allowing for capturing an input scene with a more compact sensor, thereby greatly reducing the volume of data generated during image acquisition. The third system, the tunable image projection spectrometer (TIPS), is a Fourier-domain line-scan hyperspectral imager with a tunable compression ratio. Compared to state-of-the-art spatial-domain pushbroom hyperspectral cameras, TIPS requires much fewer measurements and provides a higher light throughput. Furthermore, this dissertation will explore the impact of optical aberrations on the image quality in light field imaging, providing insights into how these imperfections influence the overall imaging performance. A lens design pipeline is proposed to mitigate key aberrations, and its effectiveness is demonstrated through the design of a light field endoscope. Additionally, a rapid calibration method has been proposed for a compact hyperspectral camera, termed the image mapping spectrometer (IMS), reducing the calibration time from weeks to hours.