Abstract
An optical current sensor based on a metal coated Hi-Bi fiber loop mirror is reported. This current sensor quantifies the current through the measurement of the temperature which varies accordingly with the magnitude of the electrical current. The temperature change is analyzed through the variation of the wavelength shift of a fringe minimum of a Hi-Bi fiber loop mirror. The minimum current detection was found to be approximately 10 A. (c) 2008 Wiley Periodicals, Inc.

Abstract
We present a potential sensor head for the simultaneous measurement of temperature and strain based on the concatenation of two long-period fiber gratings arc-induced in different fibers. Despite being the temperature and strain sensitivities of the individual gratings well defined, we demonstrate that the sensor cannot perform the simultaneous measurement of those physical parameters. This fact, results from the uncertainty in finding the determinant of the inverse matrix. (C) 2008 Wiley Periodicals, Inc.

Abstract
We present results on the measurements of polarization dependent loss (PDL) of mechanically induced long-period fibre gratings. It is shown that a proper choice of the fabrication parameters leads to a considerable reduction of PDL values.

Abstract
In this article, we present detailed results on the fabrication and characterization of mechanically induced gratings produced by winding a string around a fiber/tube set. A comparison between the mechanical and arc-induced gratings is made, which allowed its to draw some conclusions on the formation mechanisms of the latter. The usefulness of mechanical gratings in research labs is discussed and two typical applications are. also presented. (C) 2008 Wiley Periodicals, Inc.

Abstract
The formation mechanisms and properties of arc-induced gratings are intrinsically related to the temperature attained by the fiber during arc exposure. In this work, we present further results oil the estimation of the fiber temperature based oil the use of electrically insulated thermocouples. Computer simulations show that under typical arc discharge conditions, the fiber reaches steady-state thermal equilibrium in less than half a second, having a peak temperature of about 1350 degrees C (C) 2008 Wiley Periodicals, Inc.

Abstract
We discuss the writing of arc-induced long-period fiber gratings to be used as optical filters in Er/Yb fiber lasers and for flattening the gain spectra of Er-doped fiber amplifiers. A new approach for the fabrication of filters with complex profiles is also presented. (c) 2008 Wiley Periodicals, Inc.