title: Simple technique for integrating compact silicon devices within optical fibers.
abstract: In this work, we present a simple fabrication process enabling the integration of a subwavelength amorphous silicon layer inside optical fibers by means of the arc discharge technique. To assess our method, we have fabricated a compact in-line Fabry-Perot interferometer consisting of a thin (<1  μm) a-Si:H layer completely embedded within a standard single-mode optical fiber. The device exhibits low loss (1.3 dB) and high interference fringe visibility (~80%) both in reflection and transmission, due to the high refractive index contrast between silica and a-Si:H. A high linear temperature sensitivity up to 106  pm/°C is demonstrated in the range 120°C-400°C. The proposed interferometer is attractive for point monitoring applications as well as for ultrahigh-temperature sensing in harsh environments.
authors.forename: A
authors.initials: A
authors.lastname: Micco
authors.forename: A
authors.initials: A
authors.lastname: Ricciardi
authors.forename: G
authors.initials: G
authors.lastname: Quero
authors.forename: A
authors.initials: A
authors.lastname: Crescitelli
authors.forename: W J
authors.initials: WJ
authors.lastname: Bock
authors.forename: A
authors.initials: A
authors.lastname: Cusano