Shahram Mohammad Nejad

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Quantum entanglement distribution is an essential part of quantum communication and computation protocols. Here, linear optic elements are employed for distribution of quantum entanglement over long distance. Polarization beam splitters and wave plates are used for realization of an error-free protocol for broadcasting quantum entanglement in optical(More)
In this paper, accuracy improvement in the displacement measurement systems using Doppler-interferometry method is presented. The cross-talk error reduction methods are also discussed. Based on the mentioned method, a new nano-displacement measurement system is designed. In the designed system, the signal to leakage ratio for moving targets in the range(More)
In this research, an optimization approach is presented to decrease the dark current in GaAs/AlGaAs QWIPs. The dark current noise is reduced by increasing Al density in barriers, decreasing detector dimensions and increasing the periodic length of the structure. In addition, increasing the number of periods can reduce both the dark current and responsivity.(More)
This paper reveals a novel square-lattice photonic crystal fiber for dispersion compensation in a wide range of wavelengths. The 2-D finite difference frequency domain method (FDFD) with perfectly matched layers (PML) is used to investigate dispersion properties. It has been shown theoretically that it is possible to obtain high negative dispersion(More)
In this paper, design and simulation of a nanometric displacement measurement system is discussed. The combination of the Doppler effect and interferometry method is being used. A stabilized three-longitudinal-mode He-Ne laser with o A 6328 wavelength and cm 35 cavity length is used. Its primary and secondary beat frequencies are 428.60MHz, 429.27MHz, and(More)
A novel octagonal photonic crystal fiber (O-PCF) with octagonal structure is proposed. The O-PCF has ultra-flattened dispersion and negligible loss characteristics throughout the third telecommunication window (1.55 mum to 1.7 mum). The design strategy to achieve these properties is based on optimization of tow air-hole diameters. The validation of the(More)
Quantum-dot cellular automata (QCA) offers a novel alternative to the transistor paradigm. Matching architecture to QCA device characteristics is of high importance and failure to do so may squander potential gains. In this paper a new architecture for quantum-dot cellular ROM (QCROM) has been proposed. The presented architecture could raise the total(More)