Tissue perfusion and oxygenation are important biomarkers for assessment of tissue health and pathology. Optical imaging techniques using low-intensity light allow for collection of information in a non-contact manner with minimal perturbation of the tissue. Widefield illumination imaging techniques, such as laser speckle imaging and optical intrinsic imaging, enable physiological measurements across the field-of-view with relatively high spatial and temporal resolution without complex systems. At the other end of the spectrum, high intensity light can be controlled for volumetric fluorescent imaging, such as in multiphoton microscopy, or to disrupt biological structures and processes using femtosecond ablation processes to study effects of controlled perturbations for disease pathogenesis and precise surgical applications on the nanometer to the millimeter scale. The work presented in this dissertation details the construction of an open-source, low-intensity laser speckle and optical intrinsic imaging system at relatively low cost with a diverse number of physiological applications. The same system is used to answer various biomedical and biological questions regarding tissue perfusion following antibody treatment in Alzheimer’s disease and heart failure models. In addition, this work details the use of high-intensity femtosecond lasers in multiple studies, including the treatment of focal cortical epilepsy by isolation of the seizure focus, in which the developed imaging system assesses tissue health following the ablation procedure.