فهرست مطالب

  • Volume:5 Issue: 1, 2020
  • تاریخ انتشار: 1399/02/11
  • تعداد عناوین: 7
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  • Ali Farmani *, Ali Mir, Hamed Emami Nejad Pages 1-18
    In this paper, the numerical design and simulate a biosensor to detect tumors and cancerous tissues by using metamaterial structures in the microwave regime are presented. The presented structure consists of a microstrip transmission line and a split ring resonator (SRR) that form a bandpass filter and has a unique resonance frequency. Given that cancerous tissues have larger volumes of water than healthy tissues. As a result, they have a higher dielectric coefficient and conductivity which use for healthy tissues detection. By placing biological samples on SRR, its dielectric constant changes, therefore, the resonance frequency of the system changes. We can measure the types of biological tissues by measuring these changes. We used the Debye model to simulate the muscles. Also, the benefits of this biosensor are easy to use and operation, but they have lower sensitivity than terahertz biosensors. The minimum resolution for samples under test in this biosensor is 10 MHz.
    Keywords: Biosensor, Microstrip Line, Split Ring Resonator, Cancerous Tissues, Debye Model
  • Abbas Ghadimi *, Mohamad Ahmadzadeh Pages 19-34
    In this study, the effects of variation of thickness and the number of quantumwells as well as the contact length were investigated. In this paper, a vertical cavity surfaceemitting laser was simulated using of software based on finite element method. Thenumber of quantum wells was changed from 3 to 9 and the results which are related tooutput power, resonance wavelength and threshold current were extracted. Outputspecifications in terms of quantum wells thicknesses of 3.5nm to 9.5nm were evaluated.Contact thickness is also changed from 0.5μm to 3μm. Results showed that as the numberof quantum wells increased, the resonance wavelength also increased and photon energydecreased. By reducing the thickness of the quantum well, the threshold current andradiation wavelength were also decreased. By increasing the contact length, thresholdcurrent and output power increased. Temperature inside the network and density ofphoton were increased as the contact length increased
    Keywords: Quantum Well, Contact Length, Threshold Current, Output Power, Vertical Cavity Surface Emitting Laser (VCSEL)
  • Ebrahim Heidari *, Mohammad Kouhi, Heidar Izadneshan Pages 35-48

    In this paper, combining the Maxwell equations with the electron balanceequation, we obtain the inverse braking radiation absorption coefficient in a laser fusioncorona plasma. For a fixed plasma temperature, variations of the absorption coefficientversus the penetration depth into the plasma are illustrated numerically for differentvalues of laser wavelength. It is shown that, by increasing the skin depth of the laserinto the plasma, the absorption coefficient increases and tends to asymptotic value one.The effect of plasma temperature on the absorption coefficient has also beeninvestigated. In addition, the fraction of absorbed energy for resonance absorption isstudied analytically and illustrated numerically. Moreover, the fractional absorption fordifferent laser wavelengths as well as different values of incident angle is illustrated. Itcan be seen that, the maximum value of the absorption coefficient is independent of thelaser wavelength and is about 0.6 for all the wavelengths.

    Keywords: Bremsstrahlung, Corona Plasma, Resonance Absorption, Laser Fusion
  • Behnam Kazempour *, Fatemeh Moslemi Pages 49-64
    The current research is aimed to investigate the alterations of its opticalfeatures of novel adjustable three color narrowband optical filters, which comprise ofblue, green and red light. A narrowband adjustable transmission optical filters accordingto dielectric- ferroelectric heterostructures photonic structures are designed using thetransfer-matrix method (TMM). The dependence of the ferroelectric refractive index onthe external applied voltage is considered in our investigations. The transmission spectraof the designed hetrostructures with the most valuable parameters, like repeat cyclecounts number of PCs, external electric field, and incident angle for both TE and TMpolarizations are numerically investigated. The results show that the transmission peaksof three color filter shift toward the shorter wavelength by increasing the incident anglefor both polarization. Also, adjustability of the optical features of the proposedhetrostructures crystals external applied electric field is investigated .Therefore, thesecalculated results reveal an innovative idea for designing the tunable trichromatic filterand display applicationsthis.
    Keywords: Photonic Crystal, External Voltage, Three-Color Filter, Band Gap
  • Payman Bahrami, MohammadReza Shayesteh *, Majid Pourahmadi, Hadi Safdarkhani Pages 65-82

    We present the optimization of the manufacturing process of the 5nm bulk-FinFET technology by using the 3D process and device simulations. In this paper, bysimulating the manufacturing processes, we focus on optimizing the manufacturingprocess to improve the drive current of the 5nm FinFET. The improvement of drivecurrent is one of the most important issues in the FinFETs design. We first investigatethe impact of manufacturing process parameters include gate oxide thickness, type ofthe gate oxide, height of fin, and doping of the source and drain region on thresholdvoltage, breakdown voltage, and drive current of the transistor. Then, by selecting theoptimal parameters of the manufacturing process, we improve the drive current of the5nm bulk-FinFET.

    Keywords: FinFET, Manufacturing Process, Drive Current, Threshold Voltage, DIBL Effect
  • Mohammad Soroosh *, Atefeh Mirali, Ebrahim Farshidi Pages 83-100
    In this paper, we aim to design and propose a novel structure for all-opticalhalf subtractor based on the photonic crystal. The structure includes two optical switches,one power splitter, and one power combiner. The optical switches are made of theresonant rings which use the nonlinear rods for dropping operation. The footprint of thedesigned structure is about 602 μm2 that is more compact than one in most works.Furthermore, despite some works, the input signals are the same in the phase angle andthe optical power. Also, each input signal is applied to one port while this issue has notbeen considered in some works. Plane wave expansion and finite difference time domainmethods are used to calculate the band diagram and simulation of the optical wavepropagation throughout the structure, respectively. The maximum obtained rise time ofall states of the proposed device is just about 1.4 ps. Besides, the presented structure iscapable of working at the third communication window so it can be matched with opticalfiber transmission systems.
    Keywords: Kerr Effect, Optical Devices, Photonic Bandgap, Photonic Crystal, Subtractor
  • Elham Tazikeh *, Fatemeh Azimi, Fariborz Kaveh, Majid Monajemi Pages 101-120
    The opteoelectronical properties of B12N12 nano-cage was investigated in thepresent of some metals by density functional theory (DFT). After the adsorption of atoxic molecule with all complexes, the electronic properties in B11GeN12 nano-cagewere significantly increased. The UV-Vis adsorption and Infrared spectroscopy ofcyanogen chloride over the B11GeN12 have been performed by the time-dependentdensity functional theory (TD-DFT). The increasing of λmax values from the pristineB12N12 to B11GeN12, reveals that B11GeN12 nano-cages can be a suitable structure asoptic sensor for this gas detection. Overall, Because of the crystalline defect, Symmetrydisruption and the changes in the degree of polarization, the semiconductor propertyaffects these nano-cage systems. Finally, the changes of energy of gap (Eg) with asignificant charge transfer from this gas to Ge-doped nano-cage, which lead to changesof conductance of it and render this kind of system sufficient for gas detection.
    Keywords: B12N12 nano-cage, Opteoelectronical Properties, IR, UV-Vis Spectroscopies, TD-DFT Method