The quantum critical coupling conditions, where single-photon transmission goes to zero, for systems of a coupled ring resonator and atom in a one-dimensional single-mode waveguide are discussed. The quantum critical coupling conditions could be achieved even with nonvanishing intrinsic losses of the resonator and the atom, with intermode backscattering between the whispering-gallery modes of t...

Porous materials are widely used for improving sound absorption and sound transmission loss of vibrating structures. However, their efficiency is limited to medium and high frequencies. A common solution for improving their low frequency behavior while keeping an acceptable thickness is to embed resonant structures such as Helmholtz resonators. This work investigates the absorption and transmis...

ARTICLE INFO The increasing demand for good performance filters in the field of radio frequency and wireless communication leads to the advancement in the design and development of compact microstrip resonator. This paper presents the investigation and characterization microstrip resonator along with three common resonator filter design method. The first method uses cross-coupling resonators to...

We present a novel control method achieving stable multiple-degrees-of-freedom electroacoustic resonators. Such broadband absorbers, composed of a feedback-controlled electrodynamic loudspeaker, have many practical applications to real-world acoustic engineering problems, such as low-frequency industrial noise reduction in the range of [20 200 Hz]. The proposed control architecture combines a c...

We report an optical wall shear stress sensor based on the whispering gallery mode (WGM) shifts of dielectric micro-resonators. The optical resonators are spheres with a typical diameter of several hundred microns and they serve as the sensing element. The wall shear force acting on a movable plate is transmitted mechanically to the microsphere. As a result of the applied force, the shape of th...

The rate constants of nitroxide reduction by ascorbate ion were determined from a time-series measurement of ESR images, that is, ESR spatiotemporal images, which were measured with a rapid field scan L-band ESR-CT system. Two test tubes containing the phosphate buffer solutions of 3-carbamoyl-2,2,5,5-tetramethylpyrrolidin-l-yloxy (C-PROXYL) and ascorbate ion with different concentrations were ...

In this paper, we demonstrate a micro-optical wall pressure sensor concept based on the optical modes of dielectric resonators. The sensing element is a spherical micro-resonator with a diameter of a few hundred micrometers. A latex membrane that is flush mounted on the wall transmits the normal pressure to the sensing element. Changes in the wall pressure perturb the sphere's morphology, leadi...

Investigation of high amplitude pressure oscillations generated by boundary driving in shaped resonators has been carried out both theoretically and experimentally. In the theoretical modeling, the acoustic resonance in an axisymmetric resonator is studied by the Galerkin method. The resonator is exponentially expanded and the boundary driving is provided by a piston at one end. The pressure wa...

We study a resonator coupled to a generic detector and calculate the noise spectra of the two subsystems. We describe the coupled system by a closed, linear, set of Langevin equations and derive a general form for the finite frequency noise of both the resonator and the detector. The resonator spectrum is the well-known thermal form with an effective damping, frequency shift and diffusion term....

A cylindrical acoustic resonator was externally driven at the first resonance frequency by a compression driver. The acoustic energy stored in the resonator and the power dissipated per unit time were evaluated through the simultaneous measurements of acoustic pressure and velocity, in order to determine the Q value of the resonator. The resulting Q value, being employed as a measure of the dam...