Impurity effects in coaxial-connector photonic crystals: A quasi-one-dimensional periodic system

A one-dimensional coaxial connector photonic crystal has constructed from a series of standard high frequency coaxial cable "tee" and "barrel" connect ors, forming a quasi-one-dimensional periodic system with periodicities com parable to microwave wavelengths. At the appropriate frequencies, ''Bragg-l ike'' reflections of the gigahertz-frequency sinusoidal signals from the op en ends of the tee connectors result in the formation of stop bands for whi ch transmission of signals at these frequencies is forbidden. Changing the amplitude or/and phase of these reflections is analogous to the introductio n of defects (impurities) in the periodic structure and is evidenced by app earance of impurity peaks of enhanced transmission in the stop bands. This system readily allows fixing of the defect location within a unit cell to o ne particular configuration. It also allows a direct control over the locat ion of defects relative to each other. By using this system a wide variety of impurity-induced effects in photonic crystals such as surface effects, i nter-impurity interactions, and stop band widening have been demonstrated.