Curvature effects on optical emission of flexible organic light-emitting diodes.

We present an analytical model for the optical emission of a two-dimensional source in a flexible organic light-emitting diode formation with arbitrary curvature. The formulation rigorously produces closed-form analytical expressions which clearly relate the emission pattern and the device configuration, in particular, the radius of curvature. We investigate the optical properties of a prototype model through the resultant expressions, revealing that the bending induces a dramatic enhancement of emission to large angles, allowing for large viewing angle and reduced total internal reflection losses.

Analytical extraction of the recombination zone location in organic light-emitting diodes from emission pattern extrema.

We present an analytical method for extracting the recombination zone location from emission patterns produced by organic LEDs (OLEDs). The method is based on derivation of the closed-form expressions for OLED-radiated power developed in previous work and formulation of the analytical relations between the emitter position and the pattern extrema. The results are confirmed to be in good agreement with reported optical measurements.

Stable reconstruction of piecewise continuous plane stratified biological tissues via electrical impedance tomography.

Image reconstruction in electrical impedance tomography is, generally, an ill-posed nonlinear inverse problem. Regularization methods are widely used to ensure a stable solution. Herein, we present a case study, which uses a novel electrical impedance tomography method for reconstruction of layered biological tissues with piecewise continuous plane-stratified profiles.

Cavity-enhanced biosensing utilizing plasmon resonance modes.

Traditionally, surface plasmon resonance (SPR) biosensors utilize absorption of light radiation incident upon noble metal films above the total internal reflection angles. Herein we extend the SPR phenomenon to incorporate cavity plasmon resonance (CPR) excitation of metallic films at incidence angles below the critical angle. While SPR occurs for TM polarized light only and requires very specific excitation conditions, which could be disadvantageous in some practical designs, CPR does not require complicated evanescent field excitation above the critical total internal reflection angle and can be implemented for both transverse electric (TE) and transverse magnetic (TM) fields even under normal incidence (TEM).

Electrical impedance tomography method for reconstruction of biological tissues with continuous plane-stratification.

A novel electrical impedance tomography method is introduced for reconstruction of layered biological tissues with continuous plane-stratification. The algorithm implements the recently proposed reconstruction scheme for piecewise constant conductivity profiles, based on an improved Prony method in conjunction with Legendre polynomial expansion (LPE). It is shown that the proposed algorithm is capable of successfully reconstructing continuous conductivity profiles with moderate (WKB) slop.