Tunable polarization optical delay line based on a linear chirped fiber Bragg grating

Abstract

A new technique for inducing relative group delays between the orthogonal transversal propagation modes in a single mode fiber is presented. It is based on a tunable linear chirp induced in a Bragg grating written in a highly birefringent fiber by thermal means. The method can induce a relative delay over a wide range, making it possible for use in a polarization mode dispersion compensator. Figure 3(a) Reflection spectra for different temperature gradients applied to the grating (b) Relative group delay measured at 1544.75 nm for different temperature gradients Adjustable compensation of polarization mode dispersion using a high-birefringence nonlinearly chirped fiber Bragg grating, ABSTRACT: Many amazing properties of a novel electromagnetic (EM) structure, consisting a conducting grating backed with a lefthanded material (LHM) slab, are studied. High-directivity, high-power emission and narrow-beam scanning can be easily realized when this structure acts as an antenna. Simultaneously, if it works as an imaging system, extremely high resolution can also be obtained with the unique EM behaviors of the LHM. Proper usage of surface waves on apertures opened in the conducting screen makes this structure possess such attractive capabilities. In order to investigate such phenomena, a more general EM model is first developed through the equivalence principle, and then the method of moments is implemented to obtain the interesting results. All these amazing properties are clearly observed through the numerical results. Figure 1A conducting grating immersed in multiple-layered media, where an arbitrary electric source is located in Region R lN