Charge balance law based on conservation of charge is stated and employed to analyze on-chip linear, Fibonacci and exponential charge pumps. For micro-power on-chip implementations, both the positiveand the negativeplate parasitic capacitors have to be considered. Voltage conversion ratios and efficiencies can be obtained in closed form for singleand dual-branch linear charge pumps, but not for...

The direct conversion of light into work allows the driving of micron-sized motors in a contactless, controllable and continuous way. Light-to-work conversion can involve either direct transfer of optical momentum or indirect opto-thermal effects. Both strategies have been implemented using different coupling mechanisms. However, the resulting efficiencies are always very low, and high power de...

We demonstrate that traveling-wave second-harmonic generation produces amplitude-squeezed light at both the fundamental and the harmonic frequencies. Quasi-phase-matched second-harmonic conversion efficiencies approaching 60% were obtained in a 26-mm-long single-mode LiNbO(3) waveguide with pulses from a mode-locked laser at 1.53 microm. The amplitude noise of the transmitted fundamental field ...

Room temperature, broadly tunable, electrically pumped semiconductor sources in the terahertz spectral range, similar in operation simplicity to diode lasers, are highly desired for applications. An emerging technology in this area are sources based on intracavity difference-frequency generation in dual-wavelength mid-infrared quantum cascade lasers. Here we report terahertz quantum cascade las...

Förster resonant energy transfer can improve the spectral breadth, absorption and energy conversion efficiency of dye sensitized solar cells. In this design, unattached relay dyes absorb the high energy photons and transfer the excitation to sensitizing dye molecules by Förster resonant energy transfer. We use an analytic theory to calculate the excitation transfer efficiency from the relay dye...

nowadays, energy plays an important role in the economic and community development of country. consequently, performance analysis of energy systems is one of the effective methods being used to prevent waste of energy resources. among the different power generation technologies, steam power plants make a significant contribution to power generation in iran, with a share of 47 % of electricity g...

Piezoelectric components offer several potential advantages to power conversion including high density and efficiency capabilities compared magnetics at small scales. Converter architectures have been developed for efficient utilization of piezoelectrics, but without fundamental criteria designing the piezoelectric themselves. In this article, we derive figures merit achievable efficiencies han...

Four-wave mixing is observed in a silicon W1 photonic crystal waveguide. The dispersion dependence of the idler conversion efficiency is measured and shown to be enhanced at wavelengths exhibiting slow group velocities. A 12-dB increase in the conversion efficiency is observed. Concurrently, a decrease in the conversion bandwidth is observed due to the increase in group velocity dispersion in t...