Localised defects in one-dimensional periodic structures and relative phase measurements of the radiation passed through the periodic lattice

Summary form only given. Interference and diffraction of electromagnetic waves on periodic structures is a fundamental topic which has proven to be relevant and applicable to many areas of physics. Periodic structures (also known as Bragg, or photonic band gap structures) have been considered as distributed elements of the interaction space of high power sources of coherent radiation. In this role they are extremely important for a number of applications in optics and microwave electronics. Periodic lattices are considered as an alternative material for constructing wave-guiding systems, highly selective filters and pulse compressors. These are usually achieved by machining structures with specific lattice defects, which modify the properties of the lattice band-gap. The localised defect inside periodic structure creates a special state, or pass band which allows photons of specific energy and momentum to pass freely through the band gap. The measurements of the phase of the wave passed through such a structure allow one to analyse the dispersion characteristics of the lattice, which determine its suitability for a number of applications. We present the results of experimental studies of a system based on a waveguide periodic structure driven by a frequency-chirped electromagnetic wave. A comparative study of one-dimensional (1D) periodic lattices with and without localized defects is presented. The influence of the step change of the lattice period, on the structurespsila dispersion characteristics and photonic band gap are studied. Results of the measurements and analysis of the properties of periodic structures are demonstrated and discussed. The parameters of the band gap and pass band associated with the defect are studied via measurement of the relative phase of the system "photons - periodic lattice" and the amplitude of the transmitted signal.