Ali Nikoukar

IEEE 802.15.3c WPAN Standard Using Millimeter Optical Soliton Pulse Generated by a Panda Ring Resonator

A system of microring resonators (MRRs) connected to an optical modified add/drop filter system known as a Panda ring resonator is presented. The optical soliton pulse of 60 GHz frequency band can be generated and used for Wireless Personal Area Network (WPAN) applications such as IEEE 802.15.3c. The system uses chaotic signals generated by a Gaussian laser pulse propagating within a nonlinear MRRs system. The chaotic signals can be generated via a series of microring resonators, where the filtering process is performed via the Panda ring resonator system wherein ultrashort single and multiple optical soliton pulses of 60 GHz are generated and seen at the through and drop ports, respectively. The IEEE 802.15.3c standard operates at the 60 GHz frequency band, and it is applicable for a short distance optical communication such as indoor systems, where the higher transmission data rate can be performed using a high frequency band of the output optical soliton pulses. The single and multi-soliton pulses could be generated and converted to logic codes, where the bandwidths of these pulses are 5 and 20 MHz, respectively. Thus, these types of signals can be used in optical indoor systems and transmission link using appropriate components such as transmitter, fiber optics, amplifier, and receiver.

Multi optical Soliton generated by PANDA ring resonator for secure network communication

In this study, new system of quantum cryptography for network communication is proposed. Multi optical Soliton can be generated and propagate via a nonlinear modified add/drop interferometer system incorporated with a time division multiple access (TDMA) system wherein the transportation of quantum codes is performed. To increase the channel capacity and security of the signals, the PANDA ring resonator is proposed. Chaotic output signals from the PANDA ring resonator are input into the add/drop filter system. Chaotic signals can be filtered by using the add/drop filter system in which multi dark and bright solitons can be obtained and used to generate entangled quantum codes for internet security. In this study soliton pulses with FWHM and FSR of 325 pm and 880 nm are generated, respectively, where the Gaussian pulse with a centre wavelength of 1.55 μm and power of 600 mW is input into the system.

MRR quantum dense coding for optical wireless communication system using decimal convertor

In this study, simply two systems consist of series of microring resonators (MRRs) and a add/drop filter are used to generate a large bandwidth signal as localized multi wavelength, applicable for quantum dense coding (QDC) and continuous variable encoding generation using incorporated system. This technique uses the Kerr nonlinear type of light in the MRR to generate multi wavelength for desired application especially in internet security and quantum network cryptography. Quantum dense encoding can be perform by output signals of selected wavelengths which are incorporated to a polarization control system in which dark and bright optical soliton pulses with different time slot are generated. Generated dark and bright optical pulses can be converted into digital logic quantum codes using a decimal convertor system in which transmission of secured information are perform via a wireless network communication system. Results show that multi soliton wavelength, ranged from 1.55μm to 1.56μm with FWHM and FSR of 10 pm and 600 pm can be generated respectively.

Generation of discrete frequency and wavelength for secured computer networks system using integrated ring resonators

In this study, a system of discrete optical pulse generation via a series of microring resonator (MRR) is presented. Chaotic signals can be generated by an optical soliton or a Gaussian pulse within a MRR system. Large bandwidth signals of optical soliton are generated by input pulse propagating within the MRRs, which can be used to form continuous wavelength or frequency with large tunable channel capacity. Therefore, distinguished discrete wavelength or frequency pulses can be generated by using localized spatial pulses via a networks communication system. Selected discrete pulses are more suitable to generate high-secured quantum codes because of the large free spectral range (FSR). Quantum codes can be generated by using a polarization control unit and a beam splitter, incorporating to the MRRs. In this work, frequency band of 10.7 MHz and 16 MHz and wavelengths of 206.9 nm, 1448 nm, 2169 nm and 2489 nm are localized and obtained which can be used for quantum codes generation applicable for secured networks communication.

Network system engineering by controlling the chaotic signals using silicon micro ring resonator

We investigate nonlinear behaviors of light known as bifurcation and chaos within a nonlinear silicon microring resonator (SMRR). The research is used to controlling SMRRs behaviors such as chaos applicable in security coding systems. The variable parameters affect the bifurcation to be happened in smaller roundtrip among total round trip of 20000 or input power. Simulated Results show that rising of the nonlinear refractive indices, coupling coefficients and radius of the SMRR leads to descending in input power and round trips wherein the bifurcation occurs. As result, bifurcation or chaos behaviors are seen at lower input power of 44 W, where the nonlinear refractive index is n2 = 3.2×10-20 m2/W. Smallest round trips of 4770 and 5720 can be seen for the R = 40 μm and k = 0.1 respectively. The controlled chaotic signals from the SMRR are passing through a polarizer beam splitter to generate quantum binary codes which are used in wireless network communication.

Escherichia coli bacteria detection by using graphene-based biosensor

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.

An analytical model and ANN simulation for carbon nanotube based ammonium gas sensors

As one of the most interesting advancements in the field of nano technology, carbon nanotubes (CNTs) have been given special attention because of their remarkable mechanical and electrical properties and are being used in many scientific and engineering research projects. One such application facilitated by the fact that CNTs experience changes in electrical conductivity when exposed to different gases is the use of these materials as part of gas detection sensors. These are typically constructed on a Field Effect Transistor (FET) based structure in which the CNT is employed as the channel between the source and the drain. In this study, an analytical model has been proposed and developed with the initial assumption that the gate voltage is directly proportional to the gas concentration as well as its temperature. Using the corresponding formulae for CNT conductance, the proposed mathematical model is derived. An Artificial Neural Network (ANN) algorithm has also been incorporated to obtain another model for the I–V characteristics in which the experimental data extracted from a recent work by N. Peng et al. has been used as the training data set. The comparative study of the results from ANN as well as the analytical models with the experimental data in hand show a satisfactory agreement which validates the proposed models. It is observed that the results obtained from the ANN model are closer to the experimental data than those from the analytical model.

Correction: An analytical model and ANN simulation for carbon nanotube based ammonium gas sensors

Correction for ‘An analytical model and ANN simulation for carbon nanotube based ammonium gas sensors’ by Elnaz Akbari et al., RSC Adv., 2014, 4, 36896–36904.