Silicene, the Si analogue of graphene, has recently extended the short list of existing two-dimensional (2D) atomic crystals. There are many remarkable electrical properties as well as unique thermal conductivities associated with graphene and silicene making them perfect materials that possess great potential to replace and provide an even better performance than silicon in future generation semiconductor devices. It is expected that novel devices developed with these will be much faster and smaller in size than their contemporary counterparts. Although graphene and silicene display different electrical conductivity behavior, their carrier concentration has similar behavior. The current–voltage characteristics of silicene/graphene field effect transistors (FETs) have been demonstrated at different operating temperatures under the flow of different NH₃ gas concentrations. It was found that in similar conditions, the suggested model for a gas sensor based on graphene shows higher electrical conductivity compared to silicene.

Graphene is an allotrope of carbon with two‐dimensional (2D) monolayer honeycombs. A larger detection area and higher sensitivity can be provided by graphene‐based nanosenor because of its 2D structure. In addition, owing to its special characteristics, including electrical, optical and physical properties, graphene is known as a more suitable candidate compared to other materials used in the sensor application. A novel model employing a field‐effect transistor structure using graphene is proposed and the current–voltage ( I – V ) characteristics of graphene are employed to model the sensing mechanism. This biosensor can detect Escherichia coli ( E. coli ) bacteria, providing high levels of sensitivity. It is observed that the graphene device experiences a drastic increase in conductance when exposed to E. coli bacteria at 0–10 ⁵ cfu/ml concentration. The simple, fast response and high sensitivity of this nanoelectronic biosensor make it a suitable device in screening and functional studies of antibacterial drugs and an ideal high‐throughput platform which can detect any pathogenic bacteria. Artificial neural network and support vector regression algorithms have also been used to provide other models for the I – V characteristic. A satisfactory agreement has been presented by comparison between the proposed models with the experimental data.

A novel system of dark soliton array (DSA) for secured communication generated by using the multiplexed dark soliton pulses is proposed. The multi soliton pulses with relevant parameters are input into the micro ring resonators system with the radii of 10 μm and 5 μm. The dynamic dark solitons can be controlled and generated. The DSA are obtained by using a series micro ring resonators with parameters where in the wavelength range of _1 is 15016 nm, _2 is 1518 nm and _3 is 1520 nm. For security applications, the DSA can be tuned and amplified. Thus, the use of DSA for high capacity transmission can be realized by using proposed secured system. In transmission, the long distance link of the multi variable network can be performed by this DSA. Keywords Dark solition array Micro ring resonator Nonlinear behavior Uncited references [1,2,3,4,5,6,7,8,9,10,11,12,13,14] . References [1] M. Ballav A.R. Chowdhury On a study of diffraction and dispersion managed soliton in a cylindrical media Prog. Electromagn. Res. (PIER) 63 2006 33 50 [2] R. Gangwar S.P. Singh N. Singh Soliton based optical communication Prog. Electromagn. Res. (PIER) 74 2007 157 166 [3] F.G. Gharakhili M. Shahabadi M. Hakkak Bright and dark soliton generation in a left-handed nonlinear transmission line with series nonlinear capacitors Prog. Electromagn. Res. (PIER) 96 2009 237 249 [4] G. P. Agarwal, Nonlinear Fiber Optics, 4th ed.(Academic, 2007). [5] Y.S. Kivshar B. Luther-Davies Dark optical solitons: physics and applications Phys. Rep. 298 1998 81 197 [6] A.D. Kim W.L. Kath C.G. Goedde Stabilizing dark solitons by periodic phase-sensitive amplification Opt. Lett. 21 1996 465 467 [7] K. Sarapat N. Sangwara K. Srinuanjan P.P. Yupapin N. Pornsuwancharoen Novel dark-bright optical soliton conversion system and power amplification ” Opt. Eng. 48 2009 45 48 [8] B.A. Malomed A. Mostofi P.L. Chu Transformation of a dark soliton into a bright pulse J. Opt. Soc. Am. B 17 2000 507 513 [9] P.P. Yupapin N. Pornsuwanchroen S. Chaiyasoonthorn Attosecond pulse generation using nonlinear microring resonators Microwave Opt. Technol. Lett. 50 2008 3108 3110 [10] P.P. Yupapin N. Pornsuwanchroen Proposed nonlinear microring resonator arrangement for stopping and storing light IEEE Photonics Technol. Lett. 21 2009 404 406 [11] S. Mithata N. Pornsuwancharoen P.P. Yupapin A simultaneous short wave and millimeter wave generation using a soliton pulse within a nano-waveguide ” IEEE Photonics Technol. Lett. vol. 21 2009 932 934 [12] S. Mitatha Dark soliton behaviors within the nonlinear micro and nanoring resonators and applications Prog. Electromagn. Res. (PIER) 99 2009 383 404 [13] C. Finot J.M. Dudley G. Millot Generation of dark solitons by interaction between similaritons in Raman fiber amplifiers Opt. Fiber Technol. 12 2006 217 226 [14] Y. Kokubun Y. Hatakeyama M. Ogata S. Suzuki N. Zaizen Fabrication technologies for vertically coupled micro ring resonator with multilevel crossing busline and ultracompact- ring radius IEEE J. Sel. Top. Quantum Electron. 11 2005 4 10

A system of dark soliton array (DSA) for secured optical communication using the multiplexed dark soliton pulses is presented. Different wavelength of input soliton pulses with relevant parameters are fed into the rings system while the radii of the rings are 7μm, 5μm and Rd=50μm. Result shows that the free spectrum range of dark soliton input with the center wavelength of 1503nm is 0.073nm. DSA can be obtained using a series of micro ring resonators with input optical solitons of different wavelength, range from λ=1513nm to λ=1517nm. The DSA can be tuned and amplified used for many application in optical communication such as security purposes. In transmission link, the long distance link of the multi variable network can be performed using DSA