Developments and applications of microstructured fiber Bragg gratings

Nowadays, fiber Bragg gratings (FBGs) indisputably represent one of the most powerful in-fiber tools for the development of effective sensing and communication devices. Within this fiber technology, the last decade has been characterized by the birth of an emerging class of FBGs, which can be defined as microstructured FBGs. They mainly refer to two large categories: one relies on FBG writing in microstructured optical fibers, while the second deals with standard FBGs where structural defects at micro-scale are properly created within the hosting fiber by post processing techniques. This paper reviews the fabrication processes at the basis of this technology as well as its applications, discussing perspectives and challenges that lie ahead.