Low reflectivity fiber bragg grating with rectangular reflection function

摘要

Fiber Bragg gratings of low reflectivity are given a squared reflectivity function in the form of a tophat configuration having a flat top and lacking undesirable side lobes. Such a reflectivity function for a fiber Bragg grating is achieved by interfering a diffracted beam with a plane wavefront beam so as to impose a sinc function on the resulting interference pattern that imprints the grating on an optical fiber.