Language
Country/Area
No result found
Looking back at history: Why is 1978 considered a major breakthrough in fiber optic technology?
In the development of optical fiber technology, 1978 was a landmark year. That year, Ken Hill demonstrated the Fiber Bragg Grating (FBG) for the first time. This technology not only opened a new chapter in optical fiber communications, but also laid the foundation for future optical sensing and navigation technologies.
Fiber Bragg gratings expand the application potential of optical fibers by creating periodic refractive index changes in the core of the fiber that specifically reflect light of specific wavelengths.
The principle of fiber Bragg grating is very simple. When light travels between media with different refractive indexes, reflection and refraction will occur. The reflection wavelength is determined by the effective refractive index of the fiber and the period of the grating. This enables the FBG to act as an inline optical filter, filtering out certain wavelengths of light and playing an important role in sensing applications.
It is worth mentioning that the development of FBG did not happen overnight. By 1989, Gerald Meltz and colleagues were producing FBGs using lateral holography, a technology that was more flexible than early visible-light laser production methods. Research at the time showed that more efficient periodic structures could be produced using interference patterns from ultraviolet lasers, further promoting the development of fiber optic technology.
As optical filters and sensors, FBG not only plays an important role in the telecommunications field, but also finds applications in many industries such as medical and aviation.
From a theoretical perspective, the operation of fiber Bragg grating is based on the Fournel reflection of light. When light passes through media with different refractive indexes, the interaction of reflected waves and refracted waves will occur. Its reflection wavelength depends on the core refractive index of the fiber and the period of the grating. Changes in these parameters directly affect the performance of the FBG.
There are various types of fiber Bragg gratings, each type has specific application scenarios. Standard Fiber Bragg Gratings (Type I) are produced from hydrogenated and unhydrogenated optical fibers and are commonly used in a wide variety of applications. More advanced types such as regenerated fiber Bragg gratings and type II fiber Bragg gratings achieve higher performance through specific laser irradiation and material processing.
These different types of fiber Bragg gratings can produce different physical properties during the production process, including response to temperature and tolerance to elevated temperatures, which gives them great flexibility and usability in applications.
With the evolution of science and technology, we can foresee the future application of each fiber Bragg grating, which will undoubtedly show more and more potential and possibilities.
In terms of production, the manufacturing process of fiber Bragg gratings involves placing the fiber material into a high-power laser and creating the required refractive index changes through laser irradiation. In this process, manipulating changes in refractive index can achieve a variety of optical properties, further improving the stability and flexibility of FBG.
In summary, the fiber Bragg grating in 1978 not only demonstrated a breakthrough in fiber optic technology, but also became an important cornerstone in the fields of optics and telecommunications. This technology will continue to show its potential in future development and will have an indispensable impact on the development of all walks of life. Against this background, we can’t help but ask: What other technology will be able to drive innovation and change in optical fiber technology at such a fast pace in the future?
