Multiwavelength fiber laser in four mode fiber

Multiwavelength fiber laser is a nonlinear phenomenon that has a great potential for optical communication system. A stable triple-wavelength fiber laser in four mode fiber had been demonstrated experimentally by employing Sagnac filter in a simple close loop laser cavity. The Sagnac loop filter configuration was constructed using a 2 m of polarization maintaining fiber (PMF), a 3 dB coupler and a polarization controller. The laser is able to sustain triple-wavelength laser generation at 13.1 dBm output power of Erbium-Doped Fiber Amplifier (EDFA) as all laser wavelengths produced less than 0.25 nm fluctuation for over 20 min of unstoppable lasing operation. This laser configuration also has flexibility to perform single, dual and triple wavelength laser by controlling the EDFA output power

The Effect of Plasma-Treated Boron Nitride on Partial Discharge Characteristics of LDPE

Power supply reliability is a key factor in a country economic stability. It is contributed by the reliable power distributor via transmission lines, overhead or underground cables. However, the power cables and accessories are always exposed to pre-breakdown phenomena known as partial discharges (PD) which commonly occur in microvoids, defects or protrusions inside the insulation. To improve the performance of the cable insulation against PD, nanofillers are added into the insulating materials. However, to achieve superior performance of PD resistance, the nanofillers must be homogeneously dispersed into the polymer matrices with tightly bonded interfacial zones. Therefore, this could be achieved by employing method of surface functionalization by using cold atmospheric plasma to strengthen the filler/polymer interfaces. In view of foregoing, this study investigated the effects of surface treated boron nitride (BN) nanoparticles in Low Density Polyethylene (LDPE) on the PD characteristics by following CIGRE Method II at 7 kVrms applied voltage. The phase resolved PD characteristics were performed. The results revealed that by treating the nanofillers with cold plasma, the PD resistance of LDPE were highly achieved compared with the untreated BN nanofillers

The Influence of Nonlinearity Properties in Generating Octave-spanning Light

An efficient system for nonlinear parameter characterization in Highly Nonlinear Fiber (HNLF) is described using four wave mixing (FWM) technique, the FWM plays an important role in enhancing the spectrum development in most cases. The Nonlinear parameters like zero-dispersion wavelength (ZDW), chromatic dispersion (CD) and the non-linear coefficient of HNLF were successfully investigated using this technique. The results of this technique have been almost identical to factory specifications. By FWM technique, a CD at 1550 nm slope is obtained from 0.007 ps.nm-2km-1, ZDW of 1531 nm and nonlinear parameters of 10.7 W-1km-1

Microstrip Bandpass Filter with Reconfigurable Notch Response at 5.2 GHz using Defected Microstrip Structure

An investigation of a new design of short circuit stub wideband bandpass filter integrated with reconfigurable notch characteristic is presented. The wideband bandpass filter was designed from a quarter-wavelength short circuit stub with folded topology in order to reduce overall physical dimension. The U-shaped DMS was designed on a microstrip line by defecting the bandpass filter. The reconfigurable characteristic was then realized by introducing PIN diode (BAP 64-02) as a switching element that is placed on top of the U-shaped DMS. When the diode was OFF, it produced a wideband bandpass response from 3.0 GHz to 6.0 GHz. On the other hand, when the PIN diode was ON, a sharp rejection of notch response at 5.2 GHz with a very low passband transmission coefficient was finally demonstrated. This type of filter is very useful in radar and wireless communication systems

IPv6 Readiness towards Future Internet of Things (IoT)

This paper aims to examine the contribution of IPv6 infrastructure preparedness towards the readiness for IPv6 migration with emphasis on the aspect of physical infrastructure comprises of deployment, equipment and cost. Quantitative study has been carried out by using questionnaire as data collection towards 126 respondents which were network administrators and data has been analyses using regression analysis. Besides, Statistical Package for the Social Sciences (SPSS) version 19 has been used as the tool for data analysis. Findings clearly show that the roles of equipment and deployment, specifically planning, are very important factors that contribute towards the readiness for migration in an organisation. The research undoubtedly shows the contribution and importance of infrastructure aspect in the direction of the IPv6 migration. Therefore top management and policy makers should promote the upgrading of IT infrastructure in their IPv6 roadmap

Degeneration of four wave mixing in 500 m step index two mode fiber

Four wave mixing (FWM) in two-mode fiber was experimentally demonstrated at 24.7 dBm of output Erbium doped fiber amplifier (EDFA). The 0.5 km two mode fiber in laser cavity enhances the performance of four wave mixing by suppressing the homogenous broadening effect in erbium-doped fiber and perform a stable oscillation. At output EDFA approaches to 24.7 dBm, FWM is generated and the increasing of output EDFA induced the optical signal to noise ratio (OSNR) of all laser peaks

A Study of Different Substrate Material on Air Gap Radial Line Slot Array (RLSA) Antenna at 28 GHz

This paper compared the performance of the conventional Radial line slot array (RLSA) antenna structure. Two different substrates of RLSA antennas were used: The FR4 with the relative permittivity (εr) value of 4.5 and the Duroid/RT5880 with the relative permittivity (εr) value of 2.2. Both substrates had their own thickness, where the Rogers RT Duroid 5880 was thinner with the value of 0.254 mm compared to FR4 which was 1.600 mm. There were two antenna cavities, which were the FR4 hybrid with air gap and the Duroid/RT5880 hybrid with air gap. Based on different substrate, this RLSA antenna was simulated using the CST Microwave Studio simulation software and measured using the Vector Network Analyzer (VNA) equipment that can measure the frequency range (10.0 MHz to 50.0 GHz). Moreover, this RLSA antenna was presented, experimented and measured for millimeter wave frequency, which is within the frequency range (24.0 GHz to 32.0 GHz). In the middle of the rectangular, slots on radiating plate, located with fed coated of 50 Ω SSMA connector as a coaxial to waveguide transition frequency reconfigurable millimeter-wave antenna for 5G networks is presented. The results of the simulation and measurement of this RLSA antenna with different substrates show the S11 and wider value of impedance bandwidth performance in millimeter wave frequency

Windstorm hazardous area mapping using multi-criteria evaluation techniques of fuzzy logic approach.

The goal of this study to determine the most exposed area to windstorm event using fuzzy logic approach. Respond to the Sustainable Development Goal (SDG) 11 and 13, Sustainable Cities and Communities and Climate Action, this study was conducted to establish the preparedness in high-risk region. To achieve this goal, the influencing indicator was identified based on previous study. The related indicator comprises of wind speed, temperature, relative humidity, precipitation, slope, population, road, and land use. Fuzzy membership model implemented to aggregating the indicator to standard value 0 to 1. A fuzzy model was used as a method to integrate the constructed index values, and a frequency ratio was used to determine the fuzzy membership value. Different fuzzy operators (AND, OR, SUM, PRODUCT, and GAMMA) are applied to generate windstorm hazard map. The fuzzy gamma ( 3) operator, with γequal to 0.9, was used to create wind hazard map into different zones of five relative sensitivity classes: very high, high, moderate, low, and very low. 10.65% of study area has very high sensitivity towards windstorm hazard which distributed at high area (Banjaran titiwangsa), West Coast area (Pahang and West Johor) and north area (Perlis). In addition, some part in the surrounding region of Peninsular Malaysia were also identified as windstorm hazard due to the dense of urban area such at Johor Bharu and Klang Valley area. 7.20% of the study area has very-low windstorm hazard and is mainly located in the middle part

Analyzing windstorm pattern in Malaysia based on extracted Twitter data.

Wind-rain interactions often lead to severe windstorm events and consequently cause damages and fatal destructions. The increase in frequency of recent windstorm events overwhelmed the nation. Thus, efforts in obtaining and recording these events are intensified with the help of current technology. This study aims to analyze the pattern of recent windstorm events by utilizing big data and GIS. In this study, the reported windstorm events in Twitter application were extracted using R-programming. Prior to analyses, the extracted data were screened to remove any outliers found. The extracted data were selected based on the credibility of its sources to ensure the accuracy and quality. These selected data were extracted from trusted users such as Meteorological Department of Malaysia (MMD), Berita Harian, Bernama and others. This study has demonstrated the possibility of Twitter data as an alternative data source in windstorm studies based on its reasonable findings. It is exhibited that there is drastic increased of windstorm events frequency in years 2018-2020, especially in the northern and west-coast regions of Peninsular. The highest frequency was recorded in April (inter-monsoon season) while the lowest is in February and December (northeast monsoon). The increase of frequency in several locations in the Peninsular is very alarming especially in the Klang Valley since this region is highly populated and serves as Malaysia's important economic zones. Hence, risk control should be considered in this region to reduce the negative impacts as suggested in SDG11 and SDG13