Communication overhead on parallel applications is usually the most important handicap to reach a perfect speedup. The reduction of both the number and the size of messages has been the common direction of both programmers and parallelizing compilers. However, the appearance of new parallel computers allowing for the overlap of computations and communications has opened new ways to do research....

The optical characteristics of phase-locked semiconductor laser arrays are formulated in terms of the array supermodes, which are the eigenmodes of the composite-array waveguide, by using coupled-mode theory. These supermodes are employed to calculate the near fields, the far fields, and the difference in the longitudinal-mode oscillation wavelengths of the array. It is shown that the broadenin...

We report the first mode-locked operation of a resonant optical waveguide (ROW semiconductor laser array. Pulsewidths as short as 23 ps and peak powers of ower 1W are generated in a single-lobed beam. Mode-locked semiconductor lasers are attractive as compact sources of short optical pulses for use in physics measurements, for instrumentation systems, and for telecommunications applications. Su...

In this paper, after a brief overview on laser warning system (LWS), a new structure for an optical array that is used in its optical subsystem is introduced. According to the laser threats’ wavelengths (0.5 – 1.6 µm) and our desirable field of view (FOV), we used 6 lenses for gathering the incident radiation and then optimized the optical array. Lenses’ radius, their se...

A potential implementation of quantum-computation schemes in semiconductor-based structures is proposed. In particular, an array of quantum dots is shown to be an ideal quantum register for a noiseless information encoding. In addition to the suppression of phase-breaking processes in quantum dots due to the well-known phonon bottleneck, we show that a proper quantum encoding allows to realise ...

transfer matrix method (tmm) has been applied to analyze characteristics of semiconductor laser optical amplifiers. the input signal is sinusoidal modulating wave and we do not assume the modulating bias signal as well. we have shown that the distoration arises from gain modulation at low modulation frequencies, but in microwave modulation frequencies, the gain takes an average value and the re...

We report on an integrated λ/4-shifted Bragg grating array using a wafer-scale complementary metal-oxide semiconductor (CMOS) compatible process with silicon-nitride waveguides. A sidewall grating was used to simplify the fabrication process, and a sampled Bragg grating with equivalent phase-shift structure was employed to achieve an accurate λ/4 phase shift. A four-channel λ/4-shifted Bragg gr...

Self-organized dendritic crystal growth is explored to assemble uniform semiconductor nanowires into highly ordered one-dimensional microscale arrays that resemble comb structures. The individual ZnO nanowires have uniform diameters ranging from 10 to 300 nm. They are evenly spaced on a stem with a regular periodicity of 0.1-2 micrometer. Under optical excitation, each individual ZnO nanowire s...

Frequency selectivity of a novel type of multielement, multisection laterally coupled semiconductor laser array is studied using the round-trip method. It is found that such a structure should lead to a strong frequency selectivity owing to a periodic dependency of the threshold gain on the frequency. A gain-guided two-coupledcavity device was fabricated. The experimental results show excellent...

In this paper propagation of combined laser beam through atmosphere is investigated. Laser beam is combined via lens array arrangement. Turbulence is considered as an affecting factor of atmosphere and its effects on transverse coherence length (Fried parameter), peak intensity, propagation efficiency, and spot size of the laser beam is investigated. Coherent and incoherent combined beam are co...