We report on direct measurements of the magnetic near-field of metamaterial split ring resonators at terahertz frequencies using a magnetic field sensitive material. Specifically, planar split ring resonators are fabricated on a single magneto-optically active terbium gallium garnet crystal. Normally incident terahertz radiation couples to the resonator inducing a magnetic dipole oscillating pe...

8.1 Introduction Microring resonators (MR) represent a class of filters with characteristics very similar to those of Fabry–Perot filters. However, they offer the advantage that the injected and reflected signals are separated in individual waveguides, and in addition, their design does not require any facets or gratings and is thus particularly simple. MRs evolved from the fields of fibre opti...

Accurate determination of spatial soil moisture distribution and monitoring its temporal variation have a significant impact on the outcomes of hydrologic, ecologic, and climatic models. Development of a successful remote sensing instrument for soil moisture relies on the accurate knowledge of the soil dielectric constant ( soil) to its moisture content. Two existing methods for measurement of ...

I consider a topological transition resulting in an abrupt change by of the geometric (Berry’s) phase occurring in an optical modulator based on a fiber ring resonator. The topological transition, induced by modifying the birefringence along the ring, manifests itself in a narrow resonance in the transmission of the optical modulator. Contrary to the adiabatic case, the condition of critical co...

A Bragg-reflection-based ring resonator is proposed and analyzed. Closed-form expressions for the field and dispersion curves for radial Bragg gratings and photonic bandgap crystals are derived. The required gratings exhibit a chirped period and a varying index profile. Small bending radii and strong control over the resonator dispersion are possible by the Bragg confinement. Large free spectra...

We demonstrate optical bistability in a micrometer-sized silicon ring resonator based on the free-carrier dispersion effect in silicon. We measure the transfer function of the resonator showing a hysteresis loop with an input optical power of less than 10 mW. The influence of the thermal optical effect, which is minimized in the experiment by use of nanosecond pulses, is evaluated theoretically...

We demonstrate the collapse of a continuum of transverse modes in a self-imaging ring resonator that is photorefractively pumped. The resulting localized mode has an arbitrary transverse location. The mode collapse results from placing saturable photorefractive gain and loss media in spatially conjugate resonator planes. The transverse position of the localized mode is unstable under small cavi...

Fast resonance frequency modulation of a superconducting stripline resonator is investigated. The experiments are performed using a novel device which integrates a hot electron detector (HED) into a superconducting stripline ring resonator. Frequency modulation is demonstrated by both applying dc current or voltage to the HED, and by applying optical illumination, with modulation frequencies of...

A compact meander-line resonator is proposed in this paper, which could provide negative permittivity with a small unit-towavelength ratio. The meander-line structure is simple to be designed and is convenient to be controlled. Negative index materials (NIM) are realized using units composed of meander lines and split-ring resonators (SRRs), which have simultaneously negative permittivity and p...