The use of optical fiber in a multitude of applications has been increasing for several decades. This increased use has thrown up some limitations particularly in area of high-power delivery where the low damage threshold of conventional AR coatings has become an issue. Various methods such as the use end caps have been used to reduce this problem, but the fundamental issue remains, AR coatings have a low damage threshold which makes them difficult to use for high power applications. As the demand for high power delivery by optical fibers increases there is a need for more robust AR coatings for fiber end faces. AR coatings have various limitations such as very narrow bandwidth, a relatively low damage threshold compared to that of glass etc. There is need for a better solution. In this paper, we describe the use of meta-surfaces on the end of fibers that can replace standard AR coatings. These surfaces or motheye structures impart AR properties to the end faces of the fibers that are superior in almost every way. They have superior damage threshold than coatings as well as working over a broad wavelength range with no angular dependence. We compare the performance and properties of these structures with that of AR coatings
展开▼
