ABSTRACT
To handle the massive high-speed internet traffic, free space optics (FSO) or single-mode fiber (SMF) based fiber optic communication is being used everywhere across the world. These technologies are capable of providing huge bandwidth and transmitting the data at very high speed with low energy consumption. FSO is a very convenient technology to quickly expand the legacy network in the adverse geographical areas. However, its link performance is highly dependent of inconsistent weather conditions. SMF based fiber optic link has a very low loss and its performance is almost independent on the weather conditions. Though, the installation and maintenance of fibers are quite complex and costly. Individually, FSO or SMF links have their limitations and have to be integrated to leverage their benefits. In this paper, we integrated FSO/SMF links and compared the performance of the proposed architecture which is capable of providing high-speed dual-rate data transmission. The proposed architecture transmits data over either FSO or SMF or both links simultaneously and has 100% more reliability against any one of the link failures. In case of operational link failure (FSO/SMF), data may be switched to the alternative working link (SMF/FSO), simply by tuning the transmitted signal by 50 GHz. The proposed architecture is also reliable against the optical line terminal transceiver (TRx) failure as each user located in the network can be served by two transceivers (1 Gbps and 10 Gbps). The proposed architecture also supports the wavelength division multiplexing overlay transmission for broadcasting the common signal to all the available users in the networks. The architecture reduces ~ 27% of the energy consumption by utilizing the appropriate link of hybrid architecture and TRx according to weather conditions and traffic load. The integrated architecture looks attractive for providing energy-efficient, high speed, and reliable internet coverage to the areas where there is a difficulty of laying fibers and has frequent fiber faults. The architecture is useful for strengthening and boosting rural and urban development.
ABSTRACT
These days when integrated circuit (IC) designers are facing an uphill task in limiting energy/heat dissipation, reversible computing is emerging as a potential candidate with vast application in fields like nanotechnology, quantum-dot cellular automata, and low power IC. Optical reversible logics have turned up to offer high speed and low energy computations with almost no loss of input information when a certain (arithmetic or logical) operation is performed. This paper explores an optical implementation of an optimized Fredkin gate that is employed to design an $ N:2^N $ reversible decoder. The optical designs have been carried out using the electro-optic effect of a lithium niobate ($ {{\rm LiNbO}_3}$)-based Mach-Zehnder interferometer under the beam propagation method (BPM) with Optiwave's OptiBPM tool. The mathematical model of output power of these designs is also performed along with its validation in MATLAB.
ABSTRACT
The continuous quest for reversible computation that could be extensively used in applications such as digital signal processing, quantum computing, quantum-dot cellular automata, and nanotechnology has recently discovered its optical implementation as light tenders high-speed computing with the slightest information loss. The electro-optic effect of a lithium-niobate-based Mach-Zehnder interferometer is explored to configure a 4×4 modified Fredkin gate, capable of furnishing as many as 16 logical combinations, and thus showing potential of curbing the area overhead. The optical design is carried out using the beam propagation method. We have also performed the mathematical modeling and analyzed the results in MATLAB.
