Fluorinated Graphene Flakes as Overlayer on a Tilted Optical Fiber Bragg Grating for Ammonia Vapor Detection

Since the discovery of their exotic properties, graphene and graphene-related materials (GRMs) have received an extraordinary amount of interest from both academia and industry [1]. However, the production of GRMs at large volume, with consistent quality, constitutes a challenge that has hindered their practical applications. In this study, a versatile laser-based method is adopted for the single-step, scalable production of graphene flakes and graphene-nanohybrids, at ambient conditions, avoiding any wet-chemistry pre-treatment or post-processing. A thin film of few-layer turbostratic graphene flakes doped with F atoms
$(\sim 3.3\ \text{at}.\ \%)$
is deposited on the out cladding surface of an tilted optical fiber Bragg grating (TOFBG) and the response of the sensor in the detection of
$\text{NH}_{4}\text{OH}$
vapors is examined.