Finite difference transmission line model for the design of safe multi-section cables in MRI

Magnetic Resonance Materials in Physics, Biology and Medicine - To show the relevance of a simple finite difference transmission line model to help design safe implanted cables in 1.5T MRI’s...     

Microengineered Two-Dimensional Arrays of Monomode Optical Fibers

In this paper, a method to manufacture 2-D bundles of single-mode optical fibers of highly accurate pitch is presented. Electrostatic actuation of the metal-clad optical fibers is performed to align the fibers with submicrometer translational alignment accuracy. The manufacturing and alignment performance characteristics of the fiber holder are fully described. The sensitivity of the active-alignment procedure for a maximum displacement up to 90 mum is between 0.125 and 1.1 mum, depending on the clamping distance. An alignment accuracy of around 0.2 mum can be achieved with this alignment method. The combination of the electrostatic actuation with the optical monitoring of the fiber pitch in a closed-loop feedback system provides a highly accurate and sensitive alignment system.