Abstract: Biomedical optical imaging techniques have become essential for bridging fundamental scientific research and clinical applications, owing to their high resolution and absence of radiation toxicity. These advancements are crucial for driving medical innovation and improving public health outcomes. However, the integration of optical, mechanical, electrical, and control components in biomedical optical imaging systems often leads to bulky and costly equipment. This complexity limits their capacity to fulfill the growing demand for point-of-care testing (POCT) and high-resolution, minimally invasive imaging. Recent advancements in component fabrication techniques and the emergence of new technologies have positioned the design and manufacture of miniaturized biomedical optical imaging systems as a significant area of research. This review comprehensively addresses the fundamental principles, key technologies, and specific clinical applications of these systems for both in vitro and in vivo detection. Lastly, we provide insights into potential future directions in this evolving field.