The coupling of spin waves with chargeand spin-density waves is shown to be induced by a spin-dependent interaction in a quantum well, which is spin polarized by a dc magnetic field at an angle u to the symmetry axis. The mixing of the plasmonic and magnonic modes, which occurs for both intraand intersubband transitions, depends on the coupling constant of the spin-spin interaction, the tilt an...

introduction: the human skin is an active medium from the optical point of view. therefore, the diagnostic and therapeutic techniques employing light are increasing. current optical techniques are based on the measurement of the intensity of reflected absorbed or backscattered light from or within skin. studies have shown that biological tissues, and in particular skin, demonstrate polarization...

A novel multichannel vector sum phase shifter that is suitable for phased array antenna applications is demonstrated. Each channel is implemented using a distinct optical wavelength. Selective control of each channel is performed using an acousto-optic polarization coupler. The concept is successfully demonstrated for two individually controlled channels. For each channel, a continuously variab...

Spin-charge coupling is studied for a strongly confined two-dimensional hole gas subject to a perpendicular magnetic field. The study is based on spin-charge coupled drift-diffusion equations derived from quantum-kinetic equations in an exact manner. The spin-orbit interaction induces an extra out-of-plane spin polarization. This contribution exhibits a persistent oscillatory pattern in the str...

We propose and demonstrate a simple method to generate ultrawideband (UWB) pulses in the optical domain using a chirped intensity modulator and an asymmetric Mach-Zehnder interferometer (AMZI). Polarity- and shape-switchable UWB Gaussian monocycle, doublet, and triplet pulses with fractional bandwidths of 158%, 134%, and 100% and center frequencies of 6.52, 9.78, and 10.1 GHz are experimentally...

As the deployment of distributed generation continues, an increasing number of DC/AC power inverters will be interfaced into the electric grid. Groupings of these power inverters, along with distributed storage and load, are referred to as microgrids. Microgrids offer the potential for unprecedented reliability and flexibility, but also pose new control challenges. Inverters in microgrids must ...

The control of the input voltage of DC-DC converters is frequently required in photovoltaic applications. In this special situation, unlike conventional converters, the output voltage is constant and the input voltage is controlled. This paper deals with the analysis and the control of the buck converter with constant output voltage and variable input.

This paper presents an approach for teaching and learning dc-dc converter design using MathCAD. MathCAD provides advantages that greatly improve teaching and learning process especially when long and complicated design equations are involved such as those found in dc-dc converters. A design example using Excel is presented and then compared with the same example using MathCAD. Experience learne...

Step-up dc-dc converters have to cope with extremely low input voltages when used in combination with energy harvesting sources like thermogenerators, inductive generators or solar cells. The presented dc-dc converter is characterized by a high efficiency, up to 70 % in the input voltage range between 200 mV and 500 mV, and a minimum start-up voltage of 70 mV. It can deliver an output power of ...