Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. A preform is material that has undergone preliminary shaping but is not yet in its final form. In fiber optics, a preform is a piece of glass used to draw an optical fiber. The preform may consist of several pieces of a glass with different refractive index, to provide the core and cladding of the fiber. The shape of the preform may be circular, although for some applications such as double-clad fibers another form is preferred. In fiber lasers based on double-clad fiber, an asymmetric shape improves the filling factor for laser pumping. Due to the surface tension, the shape is smoothed during the drawing process, and the shape of the resulting fiber does not reproduce the sharp edges of the preform. Nevertheless, the careful polishing of the preform is important, any defects of the preform surface affect the optical and mechanical properties of the resulting fiber.

Данное издание не является оригинальным. Книга печатается по технологии принт-он-деманд после получения заказа.