Feroz Ahmed - Academia.edu (original) (raw)
Papers by Feroz Ahmed
Sensors
In this work, a highly sensitive dual-core configured microchannel-based plasmonic refractive ind... more In this work, a highly sensitive dual-core configured microchannel-based plasmonic refractive index (RI) sensor was investigated, which can be used for low RI detection. Both the sensing layer and the plasmonic material layer were built outside of the fiber design to detect the surrounding medium’s RI changes. Additionally, the effects of different plasmonic materials gold (Au), silver (Ag), and copper (Cu) toward sensitivity were investigated for the same structure. An adhesive agent was used in this work, titanium dioxide (TiO2), and was coated on top of the plasmonic material to prevent the oxidation of Ag and Cu. The coupling strength between the fundamental mode and the surface plasmon polariton (SPP) mode was observed to be very strong due to the TiO2 adhesive agent. With a resolution of 7.41 × 10−7 RIU, maximum wavelength sensitivity (WS) of 135,000 nm/RIU and amplitude sensitivity (AS) of 3239 RIU−1 were achieved using the proposed sensor while using Au as a plasmonic materi...
Photonics
This paper proposes a hexagonal photonic crystal fiber (H-PCF) structure with all circular air ho... more This paper proposes a hexagonal photonic crystal fiber (H-PCF) structure with all circular air holes in order to simultaneously achieve ultrahigh birefringence and high nonlinearity. The H-PCF design consists of an asymmetric core region, where one air hole is a reduced diameter and the air hole in its opposite vertex is omitted. The light-guiding properties of the proposed H-PCF structure were studied using the full-vector finite element method (FEM) with a circular perfectly matched layer (PML). The simulation results showed that the proposed H-PCF exhibits an ultrahigh birefringence of 3.87 × 10−2, a negative dispersion coefficient of −753.2 ps/(nm km), and a nonlinear coefficient of 96.51 W−1 km−1 at an excitation wavelength of 1550 nm. The major advantage of our H-PCF design is that it provides these desirable modal properties without using any non-circular air holes in the core and cladding region, thus making the fiber fabrication process much easier. The ultrahigh birefringe...
Sensors
In this paper, a low-loss, spiral lattice photonic crystal fiber (PCF)-based plasmonic biosensor ... more In this paper, a low-loss, spiral lattice photonic crystal fiber (PCF)-based plasmonic biosensor is proposed for its application in detecting various biomolecules (i.e., sugar, protein, DNA, and mRNA) and biochemicals (i.e., serum and urine). Plasmonic material gold (Au) is employed externally to efficiently generate surface plasmon resonance (SPR) in the outer surface of the PCF. A thin layer of titanium oxide (TiO2) is also introduced, which assists in adhering the Au layer to the silica fiber. The sensing performance is investigated using a mode solver based on the finite element method (FEM). Simulation results show a maximum wavelength sensitivity of 23,000 nm/RIU for a bio-samples refractive index (RI) detection range of 1.32–1.40. This sensor also exhibits a very low confinement loss of 0.22 and 2.87 dB/cm for the analyte at 1.32 and 1.40 RI, respectively. Because of the ultra-low propagation loss, the proposed sensor can be fabricated within several centimeters, which reduce...
2015 International Conference on Advances in Electrical Engineering (ICAEE), 2015
— This study focuses on the implementation of web based low cost yet effective remote laboratory ... more — This study focuses on the implementation of web based low cost yet effective remote laboratory system for engineering education to utilize limited resources for improving engineering student's practical knowledge as well as self learning ability. The proposed system provides practical experience to the students in the field of power electronics and telecommunications. This lab allows the students to perform experiment by controlling various experimental apparatus on real time from their home or any preferred location using the internet connection. Several experiments related to Power electronics and Telecommunications have been designed for this remote lab. The system is flexible and the range of laboratory experiments can be expanded as required without any complexity. This initializes an openly integrated environment which facilitates the sharing of not only hardware resources, but also educational material for enhancing engineering education in developing countries like Bangladesh.
2016 Future Technologies Conference (FTC), 2016
—An ultra-wideband (UWB) W-shaped patch antenna with defected ground is presented in this paper. ... more —An ultra-wideband (UWB) W-shaped patch antenna with defected ground is presented in this paper. Design, simulation and the analysis of the proposed single layer line feed antenna is done in CST Microwave Studio with 10.3 GHz operating frequency. The simulated results reveal that, the presented W-shaped line fed antenna offers a very wide bandwidth of 507 MHz ranging from 10.146 GHz to 10.653 GHz. Good voltage standing wave ratio (VSWR) and radiation pattern characteristics are obtained in the frequency band of interest, which eliminates the possible existence of trade-offs among gain, the design of the antenna and VSWR to obtain desired bandwidth enhancement. Along with the design details of the proposed antenna, simulated results are presented in this work.
2015 18th International Conference on Computer and Information Technology (ICCIT), 2015
2005 Pacific Rim Conference on Lasers & Electro-Optics, 2005
ABSTRACT Multi-wavelength lasing in an EDF laser by means of phase modulation and its spectral li... more ABSTRACT Multi-wavelength lasing in an EDF laser by means of phase modulation and its spectral lines power equalization using polarization controller, which is incorporated in a PMF Lyot-Sagnac filter are proposed and experimentally demonstrated.
Optical Review, 2003
We propose a simple method for all-fiber wavelength conversion of ultra-fast signal by means of s... more We propose a simple method for all-fiber wavelength conversion of ultra-fast signal by means of stimulated Raman scattering. The idea is based on the transference of energy from the signal as pump to a desired signal as first Stokes by stimulated Raman scattering. To minimize the walk-off between two wavelengths, we chose the input signal and the desired output signal wavelengths, equally spaced on opposite sides of the zero dispersion wavelength of the fiber. Based on this assumption, we numerically analyzed the all-fiber wavelength converter for ultra-fast signal with high output power and significantly enhanced output extinction ratio.
Optical Review, 2003
We propose a method for all-fiber ultra-fast switching using stimulated Raman scattering. It is b... more We propose a method for all-fiber ultra-fast switching using stimulated Raman scattering. It is based on the transference of energy from the signal as pump to the control signal as first Stokes by stimulated Raman scattering. In the absence of a control signal, the transference of energy from the pump signal to the generated first Stokes is negligible, which results in high output power at the pump signal wavelength. To minimize the walk-off problem between two wavelengths, we chose pump signal and control signal to be equally spaced on opposite sides of the zero dispersion wavelength of the fiber. Based on this assumption, the all-fiber ultra-fast optical switch with low power consumption and high output extinction ratio can be realized.
2007 10th International Conference on Computer and Information Technology, 2007
Abstracta channel-spacing tunable and switchable multiwavelength Erbium-doped fiber laser (MW-ED... more Abstracta channel-spacing tunable and switchable multiwavelength Erbium-doped fiber laser (MW-EDFL) operating at room temperature is studied using available experimental data. The multiwavelength generation is achieved mainly based on a single segmented ...
2012 International Conference on Informatics, Electronics & Vision (ICIEV), 2012
ABSTRACT In this paper, a new technique of BER minimization in a companding based PAPR reduction ... more ABSTRACT In this paper, a new technique of BER minimization in a companding based PAPR reduction scheme is proposed. In this approach, the conventional companding scheme is only applied for those OFDM signals whose amplitude exceeds a predefined threshold level, which results in lower BER and lower computational time. Though for the proposed scheme, improvement of the PAPR is less than the conventional companding technique, however, BER performance is improved significantly.
Journal of Networks, 2014
Modern Applied Science, 2014
Session Initiation Protocol (SIP) is a core protocol for real-time communication networks, includ... more Session Initiation Protocol (SIP) is a core protocol for real-time communication networks, including voice over internet protocol (VoIP). In this paper, author's ensured security for asterisk based SIP server using packet filtering firewall tools know as iptables. Rules are applied at Linux iptables on the basis of respective port numbers, allowing and disallowing particular IP address or IP addresses with subnet. To protect the SIP server from external attack rules are applied at Linux iptables for the useful protocols likes TCP, UDP, RTP and ICMP. A popular simulation software or network protocol analyzer known as Wireshark is used to illustrate how the iptables rules worked that applied for above protocols and shows the changes before and after applying rules. This paper also shows the asterisk server monitoring using the Linux kernel log files and asterisk command line interface (CLI) that shows the successful, unsuccessful SSH login sessions and web based login (HTTPS) with IP addresses list, SIP register request to the SIP server. In this paper, our present approach helps to prevent the SIP server from unauthorized access and attacks.
Modern Applied Science, 2014
This work mainly addresses the design a large scale network using dual stack mechanisms. We conce... more This work mainly addresses the design a large scale network using dual stack mechanisms. We concentrated on the most imperative theoretical notions of the IPv6 protocol, such as IP addressing, address allocation, routing with the OSPF and BGP protocols and routing protocols performance in dual stack network using GNS3 simulations and Wireshark Network protocol analyzer. It is evaluate a real large-scale network environment utilizing accessible end-to-end estimation methods that focuses on a large-scale IPv4 and IPv6 backbone and made performance the IPv4 and IPv6 network. In this paper, we compiled IPv6 address planning in a large scale network, performance metrics of each network in terms of time sequence graph, round trip time, TCP throughput, TCP connection time and the number of TCP connections per second that a client can establish with a remote server. It is found that, a minor degradation in the throughput of the TCP, TCP response time and a lower packet loss rate are arise in a real large scale dual stack network. We also showed a concise case study on relationship between RTT and network topology, which is cooperative to develop the performance of IPv6 networks. The result shows the proposed scheme for network migration from IPv4 to IPv6 is more reliable than other existing schemes.
Free metallic particles, inside gas insulated switchgear (GIS) apparatus are considered hazardous... more Free metallic particles, inside gas insulated switchgear (GIS) apparatus are considered hazardous to the insulation system, can be detected using acoustic sensors placed on the enclosure. From acoustic measurements, it is rather easy to determine the partial discharge pulses caused by loose or fixed particles. One can readily recognise the motion modes of the free particles by studying the acoustic signal. This paper presents the analysis of free metallic particle motion modes in GIS apparatus from acoustic measurements. The parameters such as maximum acoustic amplitude, number of acoustic pulses, mean value of maximum amplitude of 10 measurements, number of pulses which exceed the specified % of maximum amplitude characterising partial discharge activity of Al as well as Cu particles of different shapes are investigated
Japanese Journal of Applied Physics, 2001
A model for a fiber Raman laser has been numerically solved including all the interactions betwee... more A model for a fiber Raman laser has been numerically solved including all the interactions between forward and backward travelling waves. The predicted numerical results are experimentally confirmed using a fiber Raman laser with P 2 O 5-doped fiber. The maximum output power of 3.1 W at 1483.5 nm with a slope efficiency of 46% is experimentally obtained using a 300 m P 2 O 5-doped fiber. Numerical results suggest that an output power of as much as 4 W with a slope efficiency of 57% can be achieved if the Raman cavity is optimized for the same input pump power.
International journal of Computer Networks & Communications, 2014
This work mainly addresses the design a large scale network using dual stack mechanisms. We focus... more This work mainly addresses the design a large scale network using dual stack mechanisms. We focused on the most important theoretical concepts of the IPv6 protocol, such as addressing, address allocation, routing with the OSPF and BGP protocols and routing protocols performance in dual stack network using GNS3 and Wireshark simulators. we have a tendency to measure a perfect model and a true large-scale network atmosphere victimization out there end-to-end activity techniques that focuses on a large-scale IPv4 and IPv6 backbone and created performance the IPv4 and IPv6 network. In this paper, we compiled IPv6 address planning in large scale network, performance statistics of each network in terms of TCP throughput, delay jitters, packet loss rate, and round trip time. It is found that, a minor degradation within the throughput of the TCP, delay jitter, a lower packet loss rate, and a rather longer round trip time are occurred in a real large scale dual stack network.
Sensors
In this work, a highly sensitive dual-core configured microchannel-based plasmonic refractive ind... more In this work, a highly sensitive dual-core configured microchannel-based plasmonic refractive index (RI) sensor was investigated, which can be used for low RI detection. Both the sensing layer and the plasmonic material layer were built outside of the fiber design to detect the surrounding medium’s RI changes. Additionally, the effects of different plasmonic materials gold (Au), silver (Ag), and copper (Cu) toward sensitivity were investigated for the same structure. An adhesive agent was used in this work, titanium dioxide (TiO2), and was coated on top of the plasmonic material to prevent the oxidation of Ag and Cu. The coupling strength between the fundamental mode and the surface plasmon polariton (SPP) mode was observed to be very strong due to the TiO2 adhesive agent. With a resolution of 7.41 × 10−7 RIU, maximum wavelength sensitivity (WS) of 135,000 nm/RIU and amplitude sensitivity (AS) of 3239 RIU−1 were achieved using the proposed sensor while using Au as a plasmonic materi...
Photonics
This paper proposes a hexagonal photonic crystal fiber (H-PCF) structure with all circular air ho... more This paper proposes a hexagonal photonic crystal fiber (H-PCF) structure with all circular air holes in order to simultaneously achieve ultrahigh birefringence and high nonlinearity. The H-PCF design consists of an asymmetric core region, where one air hole is a reduced diameter and the air hole in its opposite vertex is omitted. The light-guiding properties of the proposed H-PCF structure were studied using the full-vector finite element method (FEM) with a circular perfectly matched layer (PML). The simulation results showed that the proposed H-PCF exhibits an ultrahigh birefringence of 3.87 × 10−2, a negative dispersion coefficient of −753.2 ps/(nm km), and a nonlinear coefficient of 96.51 W−1 km−1 at an excitation wavelength of 1550 nm. The major advantage of our H-PCF design is that it provides these desirable modal properties without using any non-circular air holes in the core and cladding region, thus making the fiber fabrication process much easier. The ultrahigh birefringe...
Sensors
In this paper, a low-loss, spiral lattice photonic crystal fiber (PCF)-based plasmonic biosensor ... more In this paper, a low-loss, spiral lattice photonic crystal fiber (PCF)-based plasmonic biosensor is proposed for its application in detecting various biomolecules (i.e., sugar, protein, DNA, and mRNA) and biochemicals (i.e., serum and urine). Plasmonic material gold (Au) is employed externally to efficiently generate surface plasmon resonance (SPR) in the outer surface of the PCF. A thin layer of titanium oxide (TiO2) is also introduced, which assists in adhering the Au layer to the silica fiber. The sensing performance is investigated using a mode solver based on the finite element method (FEM). Simulation results show a maximum wavelength sensitivity of 23,000 nm/RIU for a bio-samples refractive index (RI) detection range of 1.32–1.40. This sensor also exhibits a very low confinement loss of 0.22 and 2.87 dB/cm for the analyte at 1.32 and 1.40 RI, respectively. Because of the ultra-low propagation loss, the proposed sensor can be fabricated within several centimeters, which reduce...
2015 International Conference on Advances in Electrical Engineering (ICAEE), 2015
— This study focuses on the implementation of web based low cost yet effective remote laboratory ... more — This study focuses on the implementation of web based low cost yet effective remote laboratory system for engineering education to utilize limited resources for improving engineering student's practical knowledge as well as self learning ability. The proposed system provides practical experience to the students in the field of power electronics and telecommunications. This lab allows the students to perform experiment by controlling various experimental apparatus on real time from their home or any preferred location using the internet connection. Several experiments related to Power electronics and Telecommunications have been designed for this remote lab. The system is flexible and the range of laboratory experiments can be expanded as required without any complexity. This initializes an openly integrated environment which facilitates the sharing of not only hardware resources, but also educational material for enhancing engineering education in developing countries like Bangladesh.
2016 Future Technologies Conference (FTC), 2016
—An ultra-wideband (UWB) W-shaped patch antenna with defected ground is presented in this paper. ... more —An ultra-wideband (UWB) W-shaped patch antenna with defected ground is presented in this paper. Design, simulation and the analysis of the proposed single layer line feed antenna is done in CST Microwave Studio with 10.3 GHz operating frequency. The simulated results reveal that, the presented W-shaped line fed antenna offers a very wide bandwidth of 507 MHz ranging from 10.146 GHz to 10.653 GHz. Good voltage standing wave ratio (VSWR) and radiation pattern characteristics are obtained in the frequency band of interest, which eliminates the possible existence of trade-offs among gain, the design of the antenna and VSWR to obtain desired bandwidth enhancement. Along with the design details of the proposed antenna, simulated results are presented in this work.
2015 18th International Conference on Computer and Information Technology (ICCIT), 2015
2005 Pacific Rim Conference on Lasers & Electro-Optics, 2005
ABSTRACT Multi-wavelength lasing in an EDF laser by means of phase modulation and its spectral li... more ABSTRACT Multi-wavelength lasing in an EDF laser by means of phase modulation and its spectral lines power equalization using polarization controller, which is incorporated in a PMF Lyot-Sagnac filter are proposed and experimentally demonstrated.
Optical Review, 2003
We propose a simple method for all-fiber wavelength conversion of ultra-fast signal by means of s... more We propose a simple method for all-fiber wavelength conversion of ultra-fast signal by means of stimulated Raman scattering. The idea is based on the transference of energy from the signal as pump to a desired signal as first Stokes by stimulated Raman scattering. To minimize the walk-off between two wavelengths, we chose the input signal and the desired output signal wavelengths, equally spaced on opposite sides of the zero dispersion wavelength of the fiber. Based on this assumption, we numerically analyzed the all-fiber wavelength converter for ultra-fast signal with high output power and significantly enhanced output extinction ratio.
Optical Review, 2003
We propose a method for all-fiber ultra-fast switching using stimulated Raman scattering. It is b... more We propose a method for all-fiber ultra-fast switching using stimulated Raman scattering. It is based on the transference of energy from the signal as pump to the control signal as first Stokes by stimulated Raman scattering. In the absence of a control signal, the transference of energy from the pump signal to the generated first Stokes is negligible, which results in high output power at the pump signal wavelength. To minimize the walk-off problem between two wavelengths, we chose pump signal and control signal to be equally spaced on opposite sides of the zero dispersion wavelength of the fiber. Based on this assumption, the all-fiber ultra-fast optical switch with low power consumption and high output extinction ratio can be realized.
2007 10th International Conference on Computer and Information Technology, 2007
Abstracta channel-spacing tunable and switchable multiwavelength Erbium-doped fiber laser (MW-ED... more Abstracta channel-spacing tunable and switchable multiwavelength Erbium-doped fiber laser (MW-EDFL) operating at room temperature is studied using available experimental data. The multiwavelength generation is achieved mainly based on a single segmented ...
2012 International Conference on Informatics, Electronics & Vision (ICIEV), 2012
ABSTRACT In this paper, a new technique of BER minimization in a companding based PAPR reduction ... more ABSTRACT In this paper, a new technique of BER minimization in a companding based PAPR reduction scheme is proposed. In this approach, the conventional companding scheme is only applied for those OFDM signals whose amplitude exceeds a predefined threshold level, which results in lower BER and lower computational time. Though for the proposed scheme, improvement of the PAPR is less than the conventional companding technique, however, BER performance is improved significantly.
Journal of Networks, 2014
Modern Applied Science, 2014
Session Initiation Protocol (SIP) is a core protocol for real-time communication networks, includ... more Session Initiation Protocol (SIP) is a core protocol for real-time communication networks, including voice over internet protocol (VoIP). In this paper, author's ensured security for asterisk based SIP server using packet filtering firewall tools know as iptables. Rules are applied at Linux iptables on the basis of respective port numbers, allowing and disallowing particular IP address or IP addresses with subnet. To protect the SIP server from external attack rules are applied at Linux iptables for the useful protocols likes TCP, UDP, RTP and ICMP. A popular simulation software or network protocol analyzer known as Wireshark is used to illustrate how the iptables rules worked that applied for above protocols and shows the changes before and after applying rules. This paper also shows the asterisk server monitoring using the Linux kernel log files and asterisk command line interface (CLI) that shows the successful, unsuccessful SSH login sessions and web based login (HTTPS) with IP addresses list, SIP register request to the SIP server. In this paper, our present approach helps to prevent the SIP server from unauthorized access and attacks.
Modern Applied Science, 2014
This work mainly addresses the design a large scale network using dual stack mechanisms. We conce... more This work mainly addresses the design a large scale network using dual stack mechanisms. We concentrated on the most imperative theoretical notions of the IPv6 protocol, such as IP addressing, address allocation, routing with the OSPF and BGP protocols and routing protocols performance in dual stack network using GNS3 simulations and Wireshark Network protocol analyzer. It is evaluate a real large-scale network environment utilizing accessible end-to-end estimation methods that focuses on a large-scale IPv4 and IPv6 backbone and made performance the IPv4 and IPv6 network. In this paper, we compiled IPv6 address planning in a large scale network, performance metrics of each network in terms of time sequence graph, round trip time, TCP throughput, TCP connection time and the number of TCP connections per second that a client can establish with a remote server. It is found that, a minor degradation in the throughput of the TCP, TCP response time and a lower packet loss rate are arise in a real large scale dual stack network. We also showed a concise case study on relationship between RTT and network topology, which is cooperative to develop the performance of IPv6 networks. The result shows the proposed scheme for network migration from IPv4 to IPv6 is more reliable than other existing schemes.
Free metallic particles, inside gas insulated switchgear (GIS) apparatus are considered hazardous... more Free metallic particles, inside gas insulated switchgear (GIS) apparatus are considered hazardous to the insulation system, can be detected using acoustic sensors placed on the enclosure. From acoustic measurements, it is rather easy to determine the partial discharge pulses caused by loose or fixed particles. One can readily recognise the motion modes of the free particles by studying the acoustic signal. This paper presents the analysis of free metallic particle motion modes in GIS apparatus from acoustic measurements. The parameters such as maximum acoustic amplitude, number of acoustic pulses, mean value of maximum amplitude of 10 measurements, number of pulses which exceed the specified % of maximum amplitude characterising partial discharge activity of Al as well as Cu particles of different shapes are investigated
Japanese Journal of Applied Physics, 2001
A model for a fiber Raman laser has been numerically solved including all the interactions betwee... more A model for a fiber Raman laser has been numerically solved including all the interactions between forward and backward travelling waves. The predicted numerical results are experimentally confirmed using a fiber Raman laser with P 2 O 5-doped fiber. The maximum output power of 3.1 W at 1483.5 nm with a slope efficiency of 46% is experimentally obtained using a 300 m P 2 O 5-doped fiber. Numerical results suggest that an output power of as much as 4 W with a slope efficiency of 57% can be achieved if the Raman cavity is optimized for the same input pump power.
International journal of Computer Networks & Communications, 2014
This work mainly addresses the design a large scale network using dual stack mechanisms. We focus... more This work mainly addresses the design a large scale network using dual stack mechanisms. We focused on the most important theoretical concepts of the IPv6 protocol, such as addressing, address allocation, routing with the OSPF and BGP protocols and routing protocols performance in dual stack network using GNS3 and Wireshark simulators. we have a tendency to measure a perfect model and a true large-scale network atmosphere victimization out there end-to-end activity techniques that focuses on a large-scale IPv4 and IPv6 backbone and created performance the IPv4 and IPv6 network. In this paper, we compiled IPv6 address planning in large scale network, performance statistics of each network in terms of TCP throughput, delay jitters, packet loss rate, and round trip time. It is found that, a minor degradation within the throughput of the TCP, delay jitter, a lower packet loss rate, and a rather longer round trip time are occurred in a real large scale dual stack network.