%0 Journal Article
%T Bragg Gratings Induced in Birefringent Optical Fiber with an Elliptical Stress Cladding
%A I. K. Meshkovskiy
%A V. E. Strigalev
%A A. V. Kulikov
%A S. V. Varzhel'
%J Journal of Photonics
%D 2013
%R 10.1155/2013/936036
%X The paper presents the results of writing of type I and high-performance type II fiber Bragg gratings in birefringent optical fiber with an elliptical stress cladding by a single 20£¿ns pulse of KrF excimer laser (248£¿nm). The gratings¡¯ efficiency produced by a single pulse was up to 100%. Experimental results on visualization of these gratings are presented. 1. Introduction The first fiber Bragg grating (FBG) was obtained in 1978 [1]. About ten years later, FBG was written through a lateral surface of optical fiber for the first time [2]. Nowadays, gratings are becoming more and more widely used. Fiber Bragg gratings written in birefringent optical fibers can be used in creation of sensors for measuring physical quantities [3, 4]. To date, FBGs have been induced in birefringent optical fibers of different types: with elliptical core [5], bow-tie [6], PANDA [7], and internal elliptical cladding [8]. Here we demonstrate the results of FBG writing by a single 20£¿ns KrF excimer laser pulse in birefringent optical fiber with an elliptical stress cladding, obtained using the technology [9, 10]. This birefringent optical fiber due to its unique properties [11] is being used to create precision interferometric sensors, such as a fiber-optic gyroscope [12]. Special quadrupole winding is used in a fiber-optic gyroscope with the class of accuracy below 0.01£¿deg/h for temperature drift compensation in the fiber loop, which is the main source of phase noise [12]. To create a fiber-optic gyroscope with class of accuracy 0.01£¿deg/h and higher, the development of an active system of temperature gradients compensation in the fiber loop is required. Refractive index gratings are being widely used in temperature sensors [13, 14]. So, it is possible to measure temperature gradients inside the gyroscope fiber loop using FBGs array. For creating FBGs array, this birefringent optical fiber with an elliptical stress cladding, obtained using the technology [9, 10] with complex structure [15], which includes a core, a circular isolating cladding, an elliptical stress cladding, and a circular outer cladding, was selected. To enhance the photosensitivity of the fiber the concentration of GeO2 in its core was increased to 16£¿mol. %. Enhancing the photosensitivity at the stage of preform formation allows you to write the FBG arrays during the drawing process of optical fiber. The disadvantage of this method is an increase in linear optical losses of the fiber. Losses of birefringent optical fiber with an elliptical stress cladding with 16£¿mol. % GeO2, used in this work, are
%U http://www.hindawi.com/journals/jpho/2013/936036/