Laser Fundamentals: Operation and Applications

This lecture covers the fundamentals of laser technology, including the history and basic operation of lasers. It discusses the principles of gain, absorption, spontaneous and stimulated emission, and the significance of the Lorentz model. The instructor explains various laser systems, including gas lasers like He-Ne and CO2, and solid-state lasers. Key concepts such as beam quality, fiber coupling, and power fluctuations in lasers are introduced. The lecture also delves into ultrafast lasers, their modulation capabilities, and applications in fields like 3D fabrication. Additionally, it addresses non-linear frequency conversion techniques and their practical uses. The instructor emphasizes the importance of understanding the photon rate equations and the conditions necessary for laser operation, including the threshold conditions and gain saturation. Overall, this lecture provides a comprehensive overview of laser fundamentals and their applications in engineering.