We study the temporal and spatial dynamics of the large amplitude and frequency modulation that can be induced in an intense, few cycle laser pulse as it propagates through a rapidly ionizing gas. Our calculations include both single atom and macroscopic interactions between the non-linear medium and the laser field. We analyze the harmonic generation by such pulses and show that it is spatiall...

A retinal prosthesis is being developed for the restoration of vision in patients with retinitis pigmentosa (RP) and age-related macular degeneration (AMD). Determining optimal electrical stimulation parameters for the prosthesis is one of the most important elements for the development of a viable retinal prosthesis. Here, we investigated the effects of different charge-balanced biphasic pulse...

The results of an investigation of the performance of a time-division-addressed fiber-optic gas-sensor array by means of wavelength modulation of a distributed-feedback (DFB) laser are reported. The system performance is found to be severely limited by the extinction ratio of the optical switch used for pulse amplitude modulation. Formulas that relate the cross-talk level to the extinction rati...

We propose a modulus based zero-forcing (MZF) detection for multi-input multi-output (MIMO) channels. Traditionally, a ZF detector nulls out all interferences from other layers when detecting a current layer, which can yield suboptimal detection-performance due to the noise-enhancement issue. In many communication systems, finite alphabets such as M quadrature-amplitude-modulation (QAM) are wid...

In this paper, we present the design of complex Ultra-wideband (UWB) pulses which enables the phase-shift keying (PSK) modulation for UWB Impulse Radio (IR) Communications. Two classes of complex UWB pulses are proposed based on complex Gaussian wavelets and complex rational orthogonal wavelets respectively. Formulas in closed form are derived for a full control of the time and frequency proper...

the micro wire electrical discharge machining (micro wire-edm) process is a modern machining process with various applications in manufacturing micro-parts. the recast layer remaining on the machined surfaces is an inevitable complication of this process. this layer can subsequently affect the machined parts performance. to optimize the recast layer in the micro wire-edm of the molybdenum micro...

INTRODUCTION Neuromuscular electrical stimulation (NMES) is used to prevent muscle atrophy. However, the effect of pulse duration modulation for reducing muscle fatigue and pain is unknown. METHODS Two 2-minute stimulation protocols were applied to the knee extensors of 10 healthy individuals. In 1 session, a long pulse duration (1,000 μs) and a low current amplitude (LL), set to evoke 25% ma...

We demonstrate for the first time to our knowledge, experimentally and theoretically, that the pulse-to-pulse amplitude fluctuations that occur in pulse trains generated by actively mode-locked Er-doped fiber lasers in a repetition-rate-doubling rational-harmonic mode-locking regime are completely eliminated when the modulation frequency is properly tuned. Irregularity of the pulse position in ...

We present a method for obtaining time-resolved measurements of the amplitude modulation and the phase shift of a chirped probe pulse interacting with a femtosecond-laser-produced plasma. Based on spectral interferometry, the technique allows for single-shot measurements and keeps the temporal resolution associated with the full bandwidth of the probe pulse. We demonstrate the efficiency of thi...

This paper presents a new photonic integrated circuit, namely optical pulse-train generator, which is developed based on the transfer matrix analysis of microrings and utilizes a time-interleaved architecture. This circuit can generate multiple optical pulses sequentially from a single trigger pulse, with the timing and amplitude of each pulse determined by circuit design. Hence it can be appli...