TLDR;
This lecture introduces the course 'Laser Fundamentals and Applications', highlighting the importance of lasers due to their unique properties and wide-ranging applications. It covers the unique properties of laser light, such as monochromaticity, coherence, collimation, tunability, and high power. The lecture also provides an overview of laser applications across various sectors, including scientific research, medicine, industry, and defence.
- Lasers possess unique properties like monochromaticity, coherence and high power.
- Lasers have diverse applications across scientific, medical, industrial and military sectors.
- The course aims to cover the fundamentals of lasers and their applications.
Introduction: Why Study Lasers? [0:13]
The lecture begins by introducing the course "Laser Fundamentals and Applications," designed for undergraduates and those interested in learning about lasers. Even those with existing knowledge can benefit, as advanced applications will be covered later in the course. The fundamental question of why one should study lasers is posed, emphasising that lasers are one of the most important inventions of the last century due to their unique properties that lead to unique applications.
Unique Properties of Laser Light [3:19]
The unique properties of laser light are discussed, including monochromaticity, which refers to the very narrow linewidth of laser output, making it nearly monochromatic. Coherence is another key property, meaning all photons emitted by the laser have the same phase. Laser light is also collimated, forming a beam with directionality. Furthermore, lasers are highly tunable, allowing for a wide range of wavelengths, and they can achieve high power, resulting in extremely high energy density.
Applications of Lasers [7:55]
The lecture transitions to the diverse applications of lasers across various sectors, including scientific research, medicine, industry, and defence. Lasers are versatile devices that find applications in nearly every field. A glimpse into the specific applications within each sector is provided to illustrate the breadth of laser technology.
Scientific Applications [10:22]
In scientific applications, lasers are used extensively in spectroscopy, particularly in nonlinear optics and Raman spectroscopy, where high-intensity light is required. Laser-induced breakdown spectroscopy (LIBS) and super-resolution spectroscopies also benefit from the monochromaticity of lasers. Interferometric techniques, microscopy, and imaging heavily rely on lasers, with confocal and multiphoton microscopy being impossible without them. The Nobel Prize awarded for super-resolution microscopy highlights the importance of lasers in achieving high spatial resolution. Lasers are also crucial in astronomy, astrophysics, geology, seismology, space technology, remote sensing (LIDAR), laser cooling of atoms and molecules, and nuclear fusion research.
Medical Applications [19:45]
Medical applications of lasers include laser-assisted laparoscopic surgeries, eye surgeries (such as cataract operations using LASIK), and soft-tissue surgeries. Endoscopic surgeries are often performed or assisted by lasers, offering a non-invasive approach. Dermatology treatments frequently use lasers, and photodynamic therapy employs laser light to remove tumours or malignant cells.
Industrial and Commercial Applications [23:40]
In industry and commerce, lasers are used in everyday devices like laser scanners for printing and optical drives (CD/DVD) for data storage and retrieval. Barcode scanners in retail use lasers to read product information. Lasers are also essential in machining industries for cutting, welding, and peening metals on a large scale. Processes like cladding and drilling also utilise lasers in both macro and micro material processing, as well as in additive manufacturing. Power beaming, a method of transferring energy to spacecraft, is another critical application in the space industry. Additionally, lasers are found in remote controlling devices, optical communication, and laser shows.
Military Applications [29:54]
Military applications include the use of lasers as ammunition and weapons to destroy objects. The defence industry uses lasers for sensing and detecting threats, such as missiles or border intrusions. The use of lasers in the military has increased significantly.
Conclusion [31:16]
The lecture concludes by reiterating the vast applications of lasers in various sectors and daily life. Understanding the basics of laser technology is essential due to its wide applicability. The course aims to provide this fundamental knowledge and explore specific applications. The next class will cover the history of lasers and related topics.
