A Laser is a device that emits light through a process of optical amplification based on the stimulated emission of electromagnetic radiation. Because of its extremely high degree of monochromaticity, coherence, directionality, and brightness. Laser radiation or light has been widely used in fiber communications, industries, environmental protection, biomedicine, military, etc. This course provides the students with a thorough understanding of the fundamentals of lasers: their unique properties, their operations, and their applications. It will equip the students with the knowledge of how a coherent light is generated and amplified, the techniques on different lasers’ design, and how lasers are used in communications, data storage, industries, medicine, and biology.