Numerical simulation of the response of single gap timing RPCs with the space charge effects and Garfield++

In this article, we report the simulated response of timing RPCs of different gas gaps. A 3D Montecarlo code was developed and integrated with Garfield++ to simulate the avalanche processes with space charge effects which allow actual charge and timing spectrums. The results of this study are presented with examples of timing RPCs of gas gaps 0.02 cm and 0.03 cm

Media 1: Optical reversible programmable Boolean logic unit

Originally published in Applied Optics on 20 July 2012 (ao-51-21-5266

Universal shift register implementation using quantum dot cellular automata

Quantum-dot Cellular Automata (QCA) demands to be a promising alternative of CMOS in ultra large scale circuit integration. Arithmetic and logic unit designs using QCA are of high research interest. A layout of four and eight bit universal shift register (USR) has been proposed. Initially QCA layouts of D flip-flop with clear and 4 to 1 multiplexer are designed, which are extended to design 4 and 8-bit parallel in parallel out (PIPO) shift register. Finally the PIPO is utilized to design 4-bit and 8-bit USR. By the comparative analysis it is observed that the proposed D Flip-flop achieved 40% clock delay improvement, whereas the modified layout of 4 to 1 multiplexer achieved 30% cell count reduction and 17% clock delay reduction from the previous works. This results in 31% reduction in cell count, 45% reduction in area and 55% reduction in clock cycle delay in 8 bit USR layout

Single Mach-Zehnder interferometer based optical Boolean logic gates

In this paper, we demonstrate different optical logic gates using a single Mach-Zehnder interferometer with controlled phase modulators in each arm. The operational conditions to obtain 16 optical logic circuits, using the same design, are investigated and are a result of a constructive or destructive interference process. The proposed configuration presents significant low complexity and high scalability, and its feasibility is evaluated through numerical simulations.publishe

Theoretical analysis of all-optical clocked D flip-flop using a single SOA assisted symmetric MZI

A novel scheme for an all-optical clocked D flip-flop, with very low complexity, is proposed and numerically demonstrated. This new flip-flop configuration is based on a semiconductor optical amplifier - Mach-Zehnder interferometer (SOA-MZI), with a feedback loop, and presents two stable states determined by the phase shift between the two MZI arms. © 2011 Elsevier B.V. All rights reserved.publishe

Media 2: Polarization encoded optical N-valued inverter

Originally published in JOSA B on 01 October 2012 (josab-29-10-2852