Photosensitive optical fiber for a bragg grating filter, a method of fabricating said fiber, and a chromatic dispersion and chromatic dispersion slope compensator including a fiber of this kind

摘要

The invention proposes a photosensitive optical fiber for inscribing a Bragg grating by UV illumination, in which the photosensitivity is very high either to reduce the exposure time or to increase the contrast of the optically induced refraction index variations, whilst retaining a reasonable exposure time. Thanks to this high contrast, the fiber of the invention, imprinted with a linear chirp, in addition to correcting chromatic dispersion, is also effective in correcting the chromatic dispersion slope of a fiber of ordinary contrast, imprinted with a quadratic chirp. In a preferred embodiment, the fiber of the invention is photosensitive in the cladding. In a particularly advantageous embodiment, a non-photosensitive dopant is added to the core of said fiber to reduce the refractive index in the core, reducing the birefringence of the fiber.