Optical microscope is an important tool for researchers to study small objects. In this thesis, we will focus on the improvement of traditional microscope systems from several aspects including resolution, field of view, speed, cost, compactness, multimodality. In particular, we will investigate computational imaging methods that bypass the limitations with traditional microscope systems by combining the optical hardware design and image processing algorithm. Examples will include optimizing illumination strategy for the Fourier ptychography (FP), developing field-portable high-resolution microscope using a cellphone lens, investigating pattern-illuminated FP for fluorescence microscopy, demonstrating multimodal microscopic imaging with the use of liquid crystal display, achieving fast and accurate autofocusing for whole slide imaging system
