Showing papers by "José A. Ferrari published in 2006"
TL;DR: It is demonstrated that one can cancel the bending-induced linear birefringence in single-mode fibers by inducing a controlled anisotropy in a direction orthogonal to the bending plane by applying a lateral compressive stress on the fiber.
Abstract: We demonstrate that one can cancel the bending-induced linear birefringence in single-mode fibers by inducing a controlled anisotropy in a direction orthogonal to the bending plane. In particular, the controlled anisotropy can be generated by application of a lateral compressive stress on the fiber. This effect can be applied for the construction of birefringence-free fiber coils in Faraday sensor heads (e.g., in current sensors) to improve their sensitivity.
24 citations
TL;DR: A novel electric-field and voltage sensor based on the electro-optical properties of polymer-dispersed liquid-crystals to achieve linearization of the PDLC response and to measure transmittance changes independently of the light-intensity level variations.
Abstract: We present a novel electric-field and voltage sensor based on the electro-optical properties of polymer-dispersed liquid-crystals (PDLCs). In principle, the transmittance of PDLCs is a nonlinear function of the applied electrical field. To measure an AC field we superposed to it a known DC field. This allowed us to achieve linearization of the PDLC response and to measure transmittance changes independently of the light-intensity level variations. Validation experiments are presented.
18 citations
TL;DR: In this paper, a fiber optic variable attenuator using a dichroic polarizer sheet illuminated by a heating beam is described, which allows one to control the amount of light to be coupled into an optical fiber.
Abstract: A fiber optic variable attenuator using a dichroic polarizer sheet illuminated by a heating beam is described. The light absorbed by the polarizer induces a thermal lens, which allows one to control the amount of light to be coupled into an optical fiber. Some experiments demonstrating the thermal lens action are presented.
2 citations
TL;DR: In this paper, a defect enhancement method for periodic masks is presented, which uses the fact that periodic structures under coherent illumination generate replicas of itself displaced half period at certain distances (1/2-Talbot's length).
2 citations