title: Compact interrogator for fiber optic Bragg sensors based on an acousto-optic filter formed by photonic crystal rows of air holes.
abstract: Fiber optic sensors are typically used with expensive tunable lasers or optical spectrum analyzers for wavelength interrogation. We propose to replace the tunable laser by a broadband optical source incorporated with a novel thin linewidth acousto-optic tunable filter. It utilizes optical beam expanders constituted by photonic crystal rows of air holes in LiNbO(3) waveguide. A new design is numerically studied for a short structure (with 32 photonic crystal rows) by a two-dimensional finite-difference time-domain method. Extrapolation of these results to larger structure sizes (about 1 cm) demonstrates the possibility to develop compact interrogators with 0.4 pm wavelength resolution and 40 nm tunable range around 1550 nm.
authors.affiliation: A.V. Rzhanov Institute of Semiconductor Physics SB RAS, Prospect Lavrenteva 13, 630090 Novosibirsk, Russia. tsarev@.isp.nsc.ru
authors.forename: Andrei V
authors.initials: AV
authors.lastname: Tsarev
authors.forename: Francesco
authors.initials: F
authors.lastname: De Leonardis
authors.forename: Vittorio M N
authors.initials: VM
authors.lastname: Passaro