Differential carrier lifetime measurements were performed on index-guided oxide-confined vertical cavity surface emitting lasers operating at 980 nm. Lifetimes were extracted from laser impedance measurements at subthreshold currents, with device size as a parameter, using a simple small-signal model. The carrier lifetimes ranged from 21 ns at 9 mA, to about 1 ns at a bias close to threshold. F...

1 Parameters The paper presents the first attempt to estimates the ILC damping ring impedance and compare thresholds of the classical instabilities for several designs initially proposed for the DR. The work was carried out in the spring of 2006. Since then the choice of the DR is narrowed. Nevertheless, the analysis described below may be useful for the next iterations of the beam stability. W...

This paper studies the feedback structure associated with piezoelectric shunt damping systems and introduces a new impedance structure for multi-mode piezoelectric shunt damping. The impedance is shown to be realizable using passive circuit components and digital implementation of the associated admittance transfer function is discussed. (Some figures in this article are in colour only in the e...

In this work, we have developed an empirical expression for the input impedance of a rectangular microstrip antenna by applying the curve fitting the experimental results. We can also determine from this formula the variations of the input impedance as a function of frequency and dielectric permittivity, respectively. The results obtained were compared with those published, and we are very sati...

In recent years, an increasing number of studies has been conducted on the biophysical characteristics of the meridians and acupoints in humans and animals. The authors aim to further illustrate the objective existence and superficial locations of the meridians in various species of animals. Twelve sheep, ten goats, thirteen pigs, eleven cats, eight rabbits and seven donkeys were used to measur...