Abdul Hadi Sulaiman

Multiwavelength Fiber Laser based on Bidirectional Lyot Filter in Conjunction with Intensity Dependent Loss Mechanism

With the rapid growth of communications via the Internet, the need for an effective firewall system which has not badly affect the overall network performances has been increased. In this paper, a Field Programmable Gate Array (FPGA) -based firewall system with high performance has been implemented using Network FPGA (NetFPGA) with Xilinx Kintex-7 XC7K325T FPGA. Based on NetFPGA reference router project, a NetFPGA-based firewall system was implemented. The hardware module performs rule matching operation using content addressable memory (CAM) for higher speed data processing. To evaluate system performance, throughput, latency, and memory utilization were measured for different cases using different tools, also the number of rules that an incoming packet is subjected to was varied to get more readings using both software and hardware features. The results showed that the designed firewall system provides better performance than traditional firewalls. System throughput was doubled times of the one with Linux-Iptables firewalls.

Determinants of team effectiveness among young researchers in a Malaysian public university

Without a doubt in this era of globalization and borderless world, working in teams leads towards higher output and productivity. However, in the context of higher education settings especially among researchers, it was found that the work culture is very much aligned towards individualism efforts. Thus, the main aim of the study is to determine the influence of task interdependence and task conflict on team effectiveness. This is a quantitative study and the data was collected from 181 respondents from a local research university in Malaysia. The study found that team interdependence and task conflict contributed 22% of the variances in team effectiveness. Some suggestions are put forward to improve team effectiveness in institutions of higher learning.

Self-seeded four-wave mixing cascades utilizing fiber Bragg grating

Utilizing fiber Bragg grating (FBG), we demonstrate self-seeded four-wave mixing (FWM) cascades. Larger FWM cascades are produced at higher erbium-doped fiber amplifier (EDFA) output power using a simple scheme. Six channels are generated at the EDFA output power of 252.35 mW. The separation gap of selective dual wavelength is designed at 1.6 nm, following to the wavelength separation of the FBGs used.

Multiwavelength SOA fiber ring laser based on bidirectional Lyot filter

We have demonstrated multiwavelength fiber laser (MWFL) based on bidirectional Lyot filter and semiconductor optical amplifier (SOA). The intensity dependent loss (IDL) mechanism is utilized to obtain a flat multiwavelength spectrum of 94 wavelength lines within 5 dB bandwidth. The extinction ratio (ER) is 9 dB, while the line spacing is narrow at 0.1 nm. No polarizer is used in the experimental structure, thus the IDL mechanism is only came from SOA. When SOA current is decreased, worse wavelength lines and multiwavelength flatness is achieved. Without proper adjustment of polarization controllers (PCs), the multiwavelength performance is found degraded.

Investigation on the signal performances of pre-, post- and inline compensation of l-band dispersion compensator using Chirped Fiber Bragg grating

The placement of Chirped Fiber Bragg grating in between the span plays an important role as it affects the signal quality when it reaches the transmission end. The work highlights on the signal performance at 10 Gbps data rate after propagating through a 90 km transmission fiber. The worst BER is obtained in the inline compensation configuration as compared to pre- and post- compensation. The highest received power of -0.19 dBm with bit error rate of 2.65 E-07 is obtained in post-compensation configuration while the highest received power for post-compensation configuration is around -0.7 dBm with bit error rate of 4.95 E-07. However, pre-compensation configuration is chosen in further measurement as it gives the best power penalty as compared to other configurations when BER of 1 E-06 is used as the benchmark for the signal quality.

Pump power distribution in bidirectional pumped dual-stage L-band EDFA

Bidirectional pumped dual-stage L-band EDFA utilizing a single power splitter and pump laser has been presented in this paper. A power splitter has been used to distribute the pump power bidirectionally to pump two EDFs with different length. An average gain of 18.6 dB with average NF of 8.6 dB has been attained when the signal is equal to 0 dBm ranging from 1570 nm to 1605 nm signal. By using a single pump simultaneously with low gain ripple of less than 0.7 dB throughout the L-band transmission window.

Investigation of continuously adjustable extinction ratio in a multiwavelength SOA fiber laser based on intensity dependent transmission effect

We investigate a flat multiwavelength fiber laser (MWFL) with the extinction ratio (ER) is continuously adjustable at variation of either half wave plate (HWP) position or polarization maintaining fiber (PMF) length. The multiwavelength laser is generated from an intensity dependent transmission (IDT) effect which is induced from nonlinear polarization rotation (NPR), arising from a combination of a semiconductor optical amplifier (SOA), polarization controllers (PCs) and polarization beam splitter (PBS). The ER is continuously adjustable from 6 dB to 12 dB by rotating the HWP of a PC, as the same value of the minimum and the maximum ER can be obtained in every 45° of HWP position. The ER value is also adjustable at different length of PMF, as longer PMF is contributed to a flatter multiwavelength spectrum. The proposed MWFL design is simple, high number of lines, flat and able to adjust ER continuously.

Wavelength-spacing tunable S-band multi-wavelength fiber laser based on Lyot filter

We demonstrated a tunable S-band multiwavelength fiber laser based on semiconductor optical amplifier (SOA) and hybrid amplifier. The proposed multiwavelength utilizes a comb filter based on one PMF segment of Lyot birefringence filter for multiwavelength tunability. The wavelength spacing and the peak flatness can be altered by adjusting polarization controller (PC). The wavelength spacing tunability is either 0.4 nm or 0.8 nm with a little peak fluctuations in S-band waveband region. We obtained 6 and 10 lasing wavelengths within 10 dB bandwidth at wavelength spacing of 0.8 nm and 0.4 nm, respectively. EDFA is added into the structure and the result shows that the extinction ratio (ER) is increased to more than 30 dB which is due to higher gain provided.

Gain-flattened dual-stage L-band EDFA by using pump power distribution

An L-band erbium doped fiber amplifier (EDFA) with dual-stage architecture was proposed that gives a considerably flatten wavelength response of less than 3 dB gain variations. Gain of 25 dB was achieved throughout the L-band region (1570 nm – 1605 nm) and noise figure of less than 4.5 dB was obtained when the pump power was distributed equally to two different stages with different length of erbium-doped fiber (EDF). Without applying any gain equalizing filters, this architecture able to demonstrate a flat gain spectrum when the input signal power was varied from −30 dBm to −15 dBm.