As efficiency and power continue to increase, laser diodes will continue to replace traditional technologies, change the way existing things are handled, and at the same time promote the birth of new things. Traditionally, economists believe that technological advancement is a gradual process. More recently, the industry has focused more on disruptive innovation that can cause discontinuities. These innovations, known as general purpose technologies (GPTs), are "deep new ideas or technologies that may have a major impact on many aspects of the economy." General-purpose technology usually takes decades to develop, and even longer can lead to productivity gains. At first they were not well understood, and even after the technology was commercialized, there was a long-term lag in production adoption. Integrated circuits are a good example. Transistors were first introduced in the early 20th century, but they were widely used until late in the evening. Gordon Moore, one of Moore's Law's founders, predicted in 1965 that semiconductors would develop at a faster rate, "bringing the popularity of electronics and pushing this science into many new fields." Despite his bold and unexpectedly accurate predictions, he has undergone decades of continuous improvement before achieving productivity and economic growth. Similarly, the understanding of the dramatic development of high power semiconductor lasers is limited. In 1962, the industry first demonstrated the conversion of electrons into lasers, followed by a number of advances that have led to significant improvements in the conversion of electrons into high-yield laser processes. These improvements can support a range of important applications, including optical storage, optical networking, and a wide range of industrial applications. Reviewing these developments and the many improvements they have made highlights the potential for greater and more general impact on many aspects of the economy. In fact, with the continuous improvement of high-power semiconductor lasers, the scope of important applications will increase and have a profound impact on economic growth. High power semiconductor laser history On September 16, 1962, a team led by General Electric's Robert Hall demonstrated the infrared emission of gallium arsenide (GaAs) semiconductors, which have "strange" interference patterns, meaning coherence Laser - the birth of the first semiconductor laser. Hall originally thought that the semiconductor laser was a "long-range" because the LEDs at that time were very inefficient. At the same time, he was also skeptical because the lasers that were confirmed two years ago and existed already needed a "fine mirror." In the summer of 1962, Hall said he was shocked by the more efficient GaAs LEDs developed by the MIT Lincoln Laboratory. Subsequently, he said he was fortunate to be able to test with some high quality GaAs materials and used his experience as an amateur astronomer to develop a way to polish the edges of GaAs chips to form a cavity. Hall's successful demonstration is based on the design of radiation bounces back and forth at the interface rather than vertical bounce. He said modestly that no one "has happened to come up with this idea." In fact, Hall's design is essentially a fortunate coincidence that the semiconductor material forming the waveguide also has the property of limiting bipolar carriers at the same time. Otherwise it is impossible to implement a semiconductor laser. By using dissimilar semiconductor materials, a slab waveguide can be formed to overlap photons with carriers. These preliminary demonstrations at General Electric were a major breakthrough. However, these lasers are far from being practical devices. In order to promote the birth of high-power semiconductor lasers, it is necessary to achieve convergence of different technologies. Key technological innovations begin with an understanding of direct bandgap semiconductor materials and crystal growth techniques. Subsequent developments included the invention of double heterojunction lasers and the subsequent development of quantum well lasers. The key to further enhancing these core technologies is efficiency and the development of cavity passivation, heat dissipation and packaging technology. brightness Innovations over the past few decades have brought exciting improvements. In particular, the improvement in brightness is excellent. In 1985, the most advanced high-power semiconductor lasers at that time were able to couple 105 milliwatts of power into a 105-micron core fiber. State-of-the-art high-power semiconductor lasers can now produce more than 250 watts of 105-micron fiber with a single wavelength - a tenfold increase every eight years. Moore conceived "fixing more components on the integrated circuit" - and subsequently, the number of transistors per chip increased by a factor of 10 every seven years. Coincidentally, high-power semiconductor lasers incorporate more photons into the fiber at similar exponential rates (see Figure 1). Improvements in the brightness of high power semiconductor lasers have led to the development of various unforeseen technologies. Although the continuation of this trend requires more innovation, there is reason to believe that the innovation of semiconductor laser technology is far from complete. The well-known physics can further improve the performance of semiconductor lasers through continuous technological development. For example, quantum dot gain media can significantly improve efficiency compared to current quantum well devices. Slow axis brightness offers another level of improvement potential. New packaging materials with improved heat dissipation and extended matching will provide the enhanced power needed to continuously adjust power consumption and simplify thermal management. These key developments will provide a roadmap for the development of high-power semiconductor lasers for decades to come. Outdoor Fiber Cable,Outdoor Fiber,2 Core Outdoor Fiber Optic Cable,2 Core Outdoor Cable Zhejiang Wanma Tianyi Communication Wire & Cable Co., Ltd. , https://www.zjwmty.com
Figure 1. Brightness of high power semiconductor lasers and comparison with Moore's Law