Investigation of the role of the lateral photo-Dember effect in the generation of terahertz radiation using a metallic mask on a semiconductor.

Pulses of coherent terahertz radiation can be efficiently generated by a lateral diffusion current after ultrafast generation of photo-carriers near a metal interface on the surface of a semiconductor, this is known as the lateral photo-Dember effect. We investigate how the emission depends on the pump spot position, size, power and how it is affected by the application of an applied external bias. We study the role of the metallic mask and how it suppresses emission from the carriers diffusing under it due to a reduction of available radiation states both theoretically and experimentally.

Terahertz emission by diffusion of carriers and metal-mask dipole inhibition of radiation.

Terahertz (THz) radiation can be generated by ultrafast photo-excitation of carriers in a semiconductor partly masked by a gold surface. A simulation of the effect taking into account the diffusion of carriers and the electric field shows that the total net current is approximately zero and cannot account for the THz radiation. Finite element modelling and analytic calculations indicate that the THz emission arises because the metal inhibits the radiation from part of the dipole population, thus creating an asymmetry and therefore a net current.

Numerical simulation of optical Stark effect saturable absorbers in mode-locked femtosecond VECSELs using a modified two-level atom model.

The interaction of an optical pulse with a quantum well saturable absorber is simulated using a semi-classical two-level-atom model which has been modified to approximate spectral hole burning in the carrier distribution. Saturable absorption behaviour is examined in the limit where pulse duration approaches the carrier-carrier scattering time. For long pulses bleaching dominates the absorber response but as the pulse duration approaches the carrier-carrier scattering timescale an additional pulse shaping mechanism becomes active, allowing the absorber to continue to shorten pulses beyond the limit set by bleaching.

Efficacy and safety of onabotulinumtoxinA in patients with urinary incontinence due to neurogenic detrusor overactivity: a randomised, double-blind, placebo-controlled trial.

Background: Neurogenic detrusor overactivity (NDO) frequently results in urinary incontinence (UI) which impairs quality of life (QOL) and puts the upper urinary tract at risk.

Objective: To assess the effects of onabotulinumtoxinA (BOTOX(®), Allergan, Inc.) on UI, urodynamic variables, and QOL in incontinent patients with NDO.

Efficacy and safety of onabotulinumtoxinA for idiopathic overactive bladder: a double-blind, placebo controlled, randomized, dose ranging trial.

Purpose: Treatment options for patients with overactive bladder refractory to anticholinergics are limited. We assessed the dose response across a range of doses of onabotulinumtoxinA (BOTOX®) in patients with idiopathic overactive bladder and urinary urgency incontinence whose symptoms were not adequately managed with anticholinergics.

Materials And Methods: In a phase 2, multicenter, randomized, double-blind study, 313 patients with idiopathic overactive bladder and urinary urgency incontinence experiencing 8 or more urinary urgency incontinence episodes a week and 8 or more micturitions daily at baseline received 50, 100, 150, 200 or 300 U intradetrusor onabotulinumtoxinA, or placebo.