Cylindrical Ring Resonator Research Articles

Resonant light scattering from dielectric ring of rectangular cross section

In this paper we present the results of numerical calculations of electromagnetic properties for cylindrical ring resonators (RRs) with rectangular cross-section and a dielectric permittivity corresponding to silicon ε = 12. The calculation of the scattering spectrum (Radar Cross Section) and the field distribution of the modes were performed at in-plane polarized light excitation. The presence of four side walls in the RRs determines a richer spectrum of eigenmodes in comparison with cylindrical whispering gallery modes of disk resonators and creates more possibilities and diversity for their practical applications.

Analysis of slotted cylindrical ring resonators

Advances in mobile technology, due to the rapid growth of mobile wireless systems, coupled with stringent selectivity requirements, have led to the need for smaller and lighter high quality filters. The slotted cylindrical ring resonator is one resonator considered promising in the development of high quality compact filters for mobile communication systems due to its small size and medium to high Q-factor [1]. In this paper the Transmission Line Modeling method is used to determine the effects of using a high dielectric constant material on the size and coupling constant of the resonator. Modeling and simulations are done using Microstripes, a commercial TLM field solver from Flomerics. The paper shows that by placing a high dielectric constant material in the resonator gap the resonant size is decreased and the coupling improved.Keywords: Slotted cylindrical ring resonator, resonant frequency, electric coupling, magnetic coupling, Transmission line modeling

Single mode coupled optofluidic ring resonator dye lasers

The authors demonstrate the single mode dye laser from a coupled optofluidic ring resonator that consists of a cylindrical ring resonator fused onto the inner surface of a thin-walled capillary ring resonator. The whispering gallery modes in each ring resonator interact strongly and utilize the Vernier effect to generate single mode laser emission. The lasing threshold is 3.0 μJ/mm2. The light can be coupled out through an optical taper in contact with the capillary.

Classical Möbius-Ring Resonators Exhibit Fermion-Boson Rotational Symmetry

The behavior of coupled harmonic oscillators in systems with specified boundary conditions is typically characterized by resonances whose frequency spectra represent harmonics according to properties of the individual oscillators, the interactions between them, and the overall symmetry of the system. Here it is demonstrated that classical one- and two-dimensional radio frequency resonators constrained to a Möbius topology are the formal partners of cylindrical ring resonators, and specifically give rise to half-integral harmonic excitations that are orthogonal to the integral excitations of a ring. In particular, the half-integral harmonics are formally invariant under rotations at a minimum of 4pi rather than 2pi rad, in analogy to the rotational symmetry of fermions in quantum mechanics. The results offer a pathway for discovery in other physical systems as well as the design of novel materials and electronic instrumentation.

Analysis of ring resonators for chemical vapor sensor development

We carry out simulations based on a four-layer Mie model to systematically analyze the sensing performance of ring resonator chemical vapor sensors. Two sensor configurations are investigated, in which a polymer layer is coated on either interior or exterior surface of a fused silica cylindrical ring resonator. Upon the interaction of the polymer and the vapor analyte, the refractive index (RI) and the thickness of the polymer layer change, leading to a spectral shift in the resonant modes that are supported by the ring resonator. The RI sensitivity and thickness sensitivity are studied as a function of the polymer coating thickness and RI, the ring resonator size and wall thickness, and resonant mode order and polarization. Similarities and differences between the two sensor configurations are also discussed. Our work should provide a general guidance in development of sensitive ring resonator chemical vapor sensors.

Small filters based on slotted cylindrical-ring resonators

The realization of a small four-pole Chebyshev filter, using four matched slotted cylindrical-ring resonators, is explained. This filter, which does not need screws for tuning the resonators or couplings, is low-cost to manufacture and is suitable for mobile communications. The filter has a bandwidth of 75 MHz, centered at 1.73 GHz. To obtain the resonant frequency and Q-factor of the resonators as well as the coupling distances between the resonators, a new technique, the quasi-magneto-static finite-difference method, is used, which is also reported.