The lowest order Raviart-Thomas rectangular element is considered for solving the singular perturbation problem ?div(arp) + bp = f; where the diagonal tensor a = (" 2 ; 1) or a = (" 2 ; " 2): Global uniform convergence rates of O(N ?1) for both p and a 1=2 rp in the L 2-norm are obtained in both cases, where N is the number of intervals in both directions. The pointwise interior (away from the ...

Parametric amplification is an interesting way of artificially increasing a MEMS Quality factor and could be helpful in many kinds of applications. This paper presents a theoretical study of this principle, based on Matlab/Simulink® simulations, and proposes design guidelines for parametric structures. A new device designed with this approach is presented together with the corresponding FEM sim...

We present a theoretical analysis of the optical matrix element between the electron and hole ground states in InAs/GaAs quantum dots QDs modeled with a truncated pyramidal shape. We use an eight-band k·p Hamiltonian to calculate the QD electronic structure, including strain and piezoelectric effects. The ground state optical matrix element is very sensitive to variations in both the QD size an...

[Bio]chemical sensors, defined as devices which convert a chemical state into an electrical signal [1], have been the subject of a strong development during the past few decades. A sensor has essentially two parts (Fig. 1): a detecting element, in which the presence of an external stimulus produces a change of some property (optical, mechanical, electrical ...), and a transducing element, which...

An extended finite element method (XFEM) for the forward model of 3D optical molecular imaging is developed with simplified spherical harmonics approximation (SP(N)). In XFEM scheme of SP(N) equations, the signed distance function is employed to accurately represent the internal tissue boundary, and then it is used to construct the enriched basis function of the finite element scheme. Therefore...

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...

A scheme for photonic generation of pulsed microwave signals with tunable frequency and phase based on optical spectral-shaping and frequency-to-time mapping is proposed and experimentally demonstrated. The spectral shaping is realized by a tunable optical comb filter consisting of a differential group delay (DGD) element, a polarization modulator (PolM), and a polarizer. By passing a short opt...

Currently, cylindrical beams with radial or azimuthal polarization are being used successfully for the optical manipulation of micro- and nano-particles as well as in microscopy, lithography, nonlinear optics, materials processing, and telecommunication applications. The creation of these laser beams is carried out using segmented polarizing plates, subwavelength gratings, interference, or ligh...

We present a method of enhancing the diffraction efficiency of a hologram by placing it inside a resonant optical cavity. The diffraction efficiency improves on account of the multiple passes that the incident light undergoes inside the optical cavity. The resonance condition in this case turns out to involve both mirror reflectivity and the optical path length inside the cavity. Experimental r...

We examine experimentally the time-reversal properties of Berry's geometrical phase in one of its optical manifestations, Pancharatnam's phase, through the use of optical phase conjugation. The time-reversal symmetry of the total optical system is broken by a nonreciprocal element, a Faraday rotator. Nevertheless, we find that the geometrical part of the phase acquired by an optical wave in pas...