Open AccessLong period gratings coated with hafnium oxide by plasma-enhanced atomic layer deposition for refractive index measurements
Author(s) -
Luis Melo,
Geoff Burton,
P.R. Kubik,
Peter Wild
Publication year - 2016
Publication title -
optics express
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.394
H-Index - 271
ISSN - 1094-4087
DOI - 10.1364/oe.24.007654
Subject(s) - materials science , refractive index , atomic layer deposition , cladding (metalworking) , optics , coating , hafnium , scanning electron microscope , optoelectronics , deposition (geology) , high refractive index polymer , oxide , optical coating , layer (electronics) , composite material , zirconium , paleontology , physics , sediment , metallurgy , biology
Long period gratings (LPGs) are coated with hafnium oxide using plasma-enhanced atomic layer deposition (PEALD) to increase the sensitivity of these devices to the refractive index of the surrounding medium. PEALD allows deposition at low temperatures which reduces thermal degradation of UV-written LPGs. Depositions targeting three different coating thicknesses are investigated: 30 nm, 50 nm and 70 nm. Coating thickness measurements taken by scanning electron microscopy of the optical fibers confirm deposition of uniform coatings. The performance of the coated LPGs shows that deposition of hafnium oxide on LPGs induces two-step transition behavior of the cladding modes.