title: Thermal effects on the photoelastic coefficient of polymer optical fibers.
abstract: We measure the radial profile of the photoelastic coefficient C(r) in single-mode polymer optical fibers (POFs), and we determine the evolution of C(r) after annealing the fibers at temperatures from 40°C to 80°C. We demonstrate that C(r) in the fibers drawn from a preform without specific thermal pre-treatment changes and converges to values between 1.2 and 1.6×10-12Pa-1following annealing at 80°C. The annealed fibers display a smoothened radial profile of C(r) and a lowered residual birefringence. In contrast, the mean value of C(r) of the fiber drawn from a preform that has been pre-annealed remains constant after our annealing process and is significantly higher, i.e., 4×10-12Pa-1. The annealing process decreases the residual birefringence to a lower extent as well. These measurements indicate the impact of annealing on the thermal stability of the photoelastic coefficient of POFs, which is an essential characteristic in view of developing POF-based thermo-mechanical sensors.
authors.forename: Acheroy
authors.initials: A
authors.lastname: Sophie
authors.forename: Merken
authors.initials: M
authors.lastname: Patrick
authors.forename: Ottevaere
authors.initials: O
authors.lastname: Heidi
authors.forename: Geernaert
authors.initials: G
authors.lastname: Thomas
authors.forename: Thienpont
authors.initials: T
authors.lastname: Hugo
authors.forename: Carlos A F
authors.initials: CA
authors.lastname: Marques
authors.forename: David J
authors.initials: DJ
authors.lastname: Webb
authors.forename: Gang-Ding
authors.initials: GD
authors.lastname: Peng
authors.forename: Pawel
authors.initials: P
authors.lastname: Mergo
authors.forename: Berghmans
authors.initials: B
authors.lastname: Francis