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Physical characteristics modification of a SiGe-HBT semiconductor device for performance improvement in a terahertz detecting system

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Journal of Semiconductors 2015年第5期36卷 61-65页

作者： Hamed Ghodsi hassan kaatuzian Photonics Research Laboratory(P.R.L.) Electrical Engineering DepartmentAmir Kabir University of Technology

In order to improve the performance of a pre-designed direct conversion terahertz detector which is implemented in a 0.25 μm-SiGe-BiCMOS process, we propose some slight modifications in the bipolar section of the SiGe device physical design. Comparison of our new proposed device and the previously reported device is done by SILVACO TCAD software simulation and we have used previous experimentally reported data to confirm our software simulations. Our proposed modifications in device structural design show a present device responsivity improvement of about 10% from 1 to 1.1 A/W while the bandwidth improvement is about 218 GHz. The minimum noise equivalent power at detector output is increased by about 14.3% and finally power consumption per pixel at the maximum responsivity is decreased by about 5%.

关键词： terahertz SiGe HBT physical structure direct conversion detector

Simulation of quantum-well slipping effect on optical bandwidth in transistor laser

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Chinese Optics Letters 2009年第5期7卷 435-436页

作者： hassan kaatuzian Seyed Iman Taghavi Photonics Research Laboratory Electrical Engineering DepartmentAmirkabir University of Technology

An optical bandwidth analysis of a quantum-well （16 nm） transistor laser with 150-μm cavity length using a charge control model is reported in order to modify the quantum-well location through the base region. At constant bias current, the simulation shows significant enhancement in optical bandwidth due to moving the quantum well in the direction of collector-base junction. No remarkable resonance peak, limiting factor in laser diodes, is observed during this modification in transistor laser structure. The method can be utilized for transistor laser structure design.

关键词： well Simulation of quantum-well slipping effect on optical bandwidth in transistor laser

Analysis, design and simulation of MIM plasmonic filters with different geometries for technical parameters improvement

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Communications in Theoretical Physics 2020年第8期72卷 134-147页

作者： Sara Gholinezhad Shafagh hassan kaatuzian Mohammad Danaie Photonics Research Laboratory(PRL) Electrical Engineering DepartmentAmirkabir University of TechnologyTehranIran Electrical and Computer Engineering Faculty Semnan UniversitySemnanIran

In this paper, four optical filter topologies based on metal–insulator–metal waveguides are proposed and the designed structures are investigated numerically using finite-difference timedomain method. Triangular-shaped adjunctions have been added to the filter structures to improve their transmission spectrum. These improved structures consist of air as the insulator and silver as the metal. The relative permittivity of metal has been described via the Drude,Drude–Lorentz, and Palik models. The first filter’s transmission spectrum shows an acceptable transmittance. In the second optimized filter, the transmission spectrum has been improved. The transmittance spectrum can be tuned through adjusting the edge of the triangle in these four optimized filters. As a result, the bandwidths of resonance spectra can be adjusted. The theory of such tapered structures will be investigated by the tapered transmission line and will be solved with the transfer matrix method. This method shows a better performance and higher transmission efficiency in comparison with the basic structures. On the other hand, the final filter has been chosen as the best one because of its hexagonal resonator. The main reason for having a better result is due to a longer interaction length in comparison with the circular resonator. This in turn creates much better energy coupling and results in higher transmission.

关键词： plasmonics surface plasmon polariton(SPP) optical filter metal–insulator–metal(MIM)waveguide Drude model

Structural parameters improvement of an integrated HBT in a cascode configuration opto-electronic mixer

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Journal of Semiconductors 2013年第9期34卷 35-40页

作者： hassan kaatuzian Hadi Dehghan Nayeri Masoud Ataei Ashkan Zandi Photonics Research Laboratory(PRL) Electrical Engineering Department AmirKabir University of Technology

We analyze an integrated electrically pumped opto-electronic mixer, which consists of two InP/GalnAs hetero junction bipolar transistors （HBT）, in a cascode configuration. A new HBT with modified physical structure is proposed and simulated to improve the frequency characteristics of a cascode mixer. For the verification and calibrating software simulator, we compare the simulation results of a typical HBT, before modifying it and com paring it with empirical reported experiments. Then we examine the simulator on our modified proposed HBT to prove its wider frequency characteristics with better flatness and acceptable down conversion gain. Although the idea is examined in several GHz modulation, it may easily be extended to state of the art HBT cascode mixers in much higher frequency range.

关键词： cascode down conversion gain mixer opto-electronic photo HBT simulation

Design of ultrafast all-optical PolSK DMUX based on semiconductor optical amplifiers

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Chinese Optics Letters 2012年第9期10卷 80-84页

作者： hassan kaatuzian Hamed Ahmadi Photonics Research Lab Electrical Engineering Department Amirkabir University of Technology

A novel ultrahigh-speed all-optical demultiplexer （DMUX） with polarization-shift-keying （PolSK） modula- tion input signals is proposed. This design is based on four-wave mixing （FWM） in a semiconductor optical amplifier （SOA）. For analyzing each amplifier, we use finite-difference method （FDM） based on solution of the traveling wave coupled equations. Using numerical simulation, the all-optical DMUX is theoretically realized at 40 Gb/s. We also study the relation between optical confinement factor and thickness of active layer of the SOA section successfully, and investigate the increasing effect of confinement factor on the DMUX optical output power. With this work, the confinement factor is increased from 0.3 to 0.48, and as a result, the output power approximately twice of its initial value is achieved. Moreover, the effects of polarization dependence of SOA on the output performance of all-optical DMUX for PolSK signal are theoretically investigated in detail.

关键词： Design of ultrafast all-optical PolSK DMUX based on semiconductor optical amplifiers DMUX SOA

Graded index separate confinement heterostructure transistor laser:analysis of various confinement structures

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Chinese Optics Letters 2017年第6期15卷 92-96页

作者： Mohammad Hosseini hassan kaatuzian Iman Taghavi Photonics Research Laboratory Electrical Engineering DepartmentAmirkabir University of Technology Electrical and Computer Engineering Department Georgia Institute of Technology

A new configuration of the confinement structure is utilized to improve optoelectronic performance, including threshold current, ac current gain, optical bandwidth, and optical output power of a single quantum well transistor laser. Considering the drift component in addition to the diffusion term in electron current density, a new continuity equation is developed to analyze the proposed structures. Physical parameters, including electron mobility, recombination lifetime, optical confinement factor, electron capture time, and photon lifetime, are calculated for new structures. Based on solving the continuity equation in separate confinement heterostructures, the threshold current reduces 67%, the optical output power increases 37%, and the-3 d B optical bandwidth increases to 21 GHz（compared to 19.5 GHz in the original structure） when the graded index layers of AlξGa1-ξAs（ξ：0.05 → 0 in the left side of quantum well, ξ：0 → 0.02 in the right side of quantum well） are used instead of uniform Ga As in the base region.

关键词： confinement transistor continuity lifetime bandwidth capture utilized instead separate drift

Frequency Domain Approach for Face Recognition Using Optical Vanderlugt Filters

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Optics and Photonics Journal 2016年第8期6卷 94-100页

作者： Faranak Heidari hassan kaatuzian Armin Alizadeh Photonics Research Lab (PRL) Electrical Engineering Department Amirkabir University of Technology Tehran Iran

In this paper human face machine identification is experienced using optical correlation techniques in spatial frequency domain. This approach is tested on ORL dataset of faces which includes face images of 40 subjects, each in 10 different positions. The examined optical setup relies on optical correlation based on developing optical Vanderlugt filters and its basics are described in this article. With the limitation of face database of 40 persons, the recognition is examined successfully with nearly 100% of accuracy in matching the input images with their respective Vanderlugt synthesized filters. Software simulation is implemented by using MATLAB for face identification.

关键词： Frequency Domain Approach for Face Recognition Using Optical Vanderlugt Filters

Analysis and Investigation of Slow Light Based on Plasmonic Induced Transparency in Metal-Dielectric-Metal Ring Resonator in a Waveguide System with Different Geometrical Designs

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Optics and Photonics Journal 2016年第8期6卷 177-184页

作者： Mehdi hassani Keleshtery hassan kaatuzian Ali Mir Electronics Group Faculty of Engineering Department Lorestan University Khorramabad Iran Photonics Research Laboratory (PRL) Electrical Engineering Department Amirkabir University of Technology Tehran Iran

In this paper we will try to create, propose and analyze structure of a slow light device, based on plasmonic induced transparency in a metal-dielectric-metal based ring resonator. Group index by first design about 37 and second design about 35 earned. The proposed dielectric material is Poly Methyl Meta Acrylate (PMMA) sandwiched by gold metal cladding. Finite Element Method-con- ducted Electromagnetic simulations are employed to evaluate the plasmonic designs for behavior of slow light. The signal and pump wavelength are assumed to be 830 nm and 1550 nm respectively in the systems. The overall length of the plasmonic slow light system is 600 nm. In a wide range of frequency bands, the optical properties of metals can be described with a plasma model. The optical signal can be achieved with the use of surface waves on the boundary between the insulating materials and metals with dimensions smaller than the diffraction limit. The main goal, is estimation of optical characteristics such as bandwidth, the Real and Imaginary parts of refractive index, group velocity and slow down factor in such optical devices. The obtained results and observations, can be useful in basic research and the production of highly integrated plasmonic devices.

关键词： Slow Light Plasmonic Induced Transparency Metal-Dielectric-Metal Poly Methyl Meta Acrylate (PMMA) Surface Plasmon Polaritons Refractive Index Slow Down Factor

Simulation and Design of a Submicron Ultrafast Plasmonic Switch Based on Nonlinear Doped Silicon MIM Waveguide

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Journal of Computer and Communications 2013年第7期1卷 23-26页

作者： Ahmad Naseri Taheri hassan kaatuzian Photonics Research Laboratory (PRL) Electrical Eng. Dept Amirkabir University of Technology Tehran Iran.

We propose and analyze a submicron stub-assisted ultrafast all-optical plasmonic switch based on nonlinear MIM waveguide. It is constructed by two silicon stub filters sandwiched by silver cladding. The signal wavelength is assumed to be 1550 nm. The simulation results show a ?14.66 dB extinction ratio. Downscaling the silicon waveguide in MIM structure leads to enhancement of the effective Kerr nonlinearity due to tight mode confinement. Also, using O+ ions implanted into silicon, the switching time less than 10 ps and a delay time less than 8 fs are achieved. The overall length of the switch is 550 nm.

关键词： Plasmonics Silicon Based All-Optical Switch Stub Filter Metal-Insulator-Metal Waveguide Nonlinear Kerr Effect