New techniques for multiple wavelength fiber laser generation based on edfa and tdfa

Multiple wavelength fiber laser (MWFL) can be a potential source for microwave generation as the conventional microwave generator have several issues in generating high frequency. In order to be such source, the MWFL must have the following criterion; a great number of comb lines, a compact design, adjustable and switchable wavelength spacing, as well as stable MWFL. Four main research studies are successfully demonstrated in efforts to improve the performance of MWFL either based on erbium doped fiber amplifier (EDFA) or thulium doped fiber amplifier (TDFA). The first study is related to a numerical analysis of Brillouin erbium fiber laser (BEFL). In this study, the elements of EDFA and stimulated Brillouin scattering (SBS) effect are thoroughly investigated. It is found that the optimum length of erbium doped fiber (EDF) is 10 m and the residual waves exist in the forward propagation. These findings successfully generate up to 10 Stokes lines. The second research work is related to an experimental study on the four-wave mixing cascades (FWMC) seeded by a BEFL. In the experiment, the Brillouin pump (BP) wavelength is varied to optimize the number of comb lines. Experimental results show that up to 80 comb lines is generated when the BP wavelength is varied at 1560 nm. In the third research work, an experimental setup of dual-wavelength Brillouin thulium fiber laser (BTFL) with an adjustable Brillouin frequency spacing (BFS) is designed. The proposed design incorporates a micro air gap in the BTFL cavity. This study successfully generates dual wavelength with single-, double-, and triple- BFS which has wavelength spacing of 0.084 nm, 0.166 nm, and 0.254 nm, respectively. The fourth research work is associated with the generation of multiple wavelength thulium-doped fiber laser (TDFL) by splicing single mode fiber (SMF) at both ends of 2.5 m two-mode step index fiber (TMSIF). The proposed scheme successfully generates up to 8 stable laser lines with wavelength spacing of 0.8 nm. Based on the experimental results of BTFL and TDFL, the proposed scheme is able to generate a microwave signals for 10 GHz, 20 GHz, 30 GHz, and 100 GHz region, respectively

Development of an electromagnetic numerical solver based on the finite difference time domain (FDTD) technique for research and teaching purposes

A 1D-FDTD code was developed to support plane wave excitation in 3D-FDTD domain and the code was developed using C++ programming language. First-order Mur absorbing boundary condition (ABC) is applied to keep outgoing electric and magnetic fields from being reflected into the problem space. In this thesis, the performance of 1D-FDTD scheme is then evaluated on several medium including free space, lossless dielectric medium, lossy dielectric medium and good conductors. Sine-Gaussian technique is used to excite field signal in the 1D-FDTD simulation domain and the simulation have been carried out to analyze the performance of the scheme. From the results, the 1D-FDTD scheme shows good expected results on all applied conditions. The integration of 1D-FDTD scheme into the 3D-FDTD solver is realized through the implementation of Total Field Scattered Field (TFSF) technique. The technique is used to excite plane wave into the 3D-FDTD domain and will be used for future wave propagation studies. All simulation results presented in this work were analyzed using OriginPro software

Total quality management (TQM): decision making process model at planning phase for housing development in Malaysia

The main aim of this study is to develop a process model for decision making in the planning phase of housing development in Malaysia. This paper identifies the decision making practiced among Malaysian housing developers at planning phase and examines the three main parts in making decisions which are methods, tools and informations. The paper then investigates whether the three main parts (methods, tools and information) are strongly related to the decision making process. This paper involves the development of a theoretical model by integrates the models developed by numerous authors and researchers on the subject of decision making. The descriptive statistical technique is conducted and the regression analysis is organize using Structural Equation Modelling (SEM) with AMOS to see the relationship between the three main parts (methods, tools and information) in making the decision. Thus, this paper is beneficial as a guide for housing developers and governments in making a decision at planning phase for housing development

Dual-wavelength thulium fluoride fiber laser based on SMF-TMSIF-SMF interferometer as potential source for microwave generationin 100-GHz region

A dual-wavelength thulium-doped fluoride fiber (TDFF) laser is presented. The generation of the TDFF laser is achieved with the incorporation of a single modemultimode- single mode (SMS) interferometer in the laser cavity. The simple SMS interferometer is fabricated using the combination of two-mode step index fiber and single-mode fiber. With this proposed design, as many as eight stable laser lines are experimentally demonstrated. Moreover, when a tunable bandpass filter is inserted in the laser cavity, a dual-wavelength TDFF laser can be achieved in a 1.5-μm region. By heterodyning the dual-wavelength laser, simulation results suggest that the generated microwave signals can be tuned from 105.678 to 106.524 GHz with a constant step of �0.14 GHz. The presented photonics-based microwave generation method could provide alternative solution for 5G signal sources in 100-GHz region

Switchable 10, 20, and 30 GHz region photonics-based microwave generation using thulium-doped fluoride fiber laser

In this work, switchable 10, 20, and 30 GHz region photonics-based microwave generation in a fiber laser cavity is proposed and demonstrated. The microwave generation is based on the beating of a dual-wavelength thuliumdoped fluoride fiber laser. With the aid of a micro-air gap in an adapter, single, double, and triple Brillouin spacing can be generated in a single fiber laser cavity without re-routing the cavity. The wavelength spacing of the dual wavelengths that are induced by the single, double, and triple Brillouin spacing are 0.084, 0.166, and 0.254 nm, respectively, at a center wavelength of 1490 nm. In addition, a numerical calculation is performed using MATLAB to prove the generation of microwave signals at 11.34, 22.44, and 34.3 GHz. With the advantage of switchability among the 10, 20, and 30 GHz regions, the proposed photonics-based microwave generation is promising for the advancement of 5G technologies

Dual-wavelength thulium fluoride fiber laser based on SMF-TMSIF-SMF interferometer as potential source for microwave generation in 100-g hz region

A dual-wavelength thulium-doped fluoride fiber (TDFF) laser is presented. The generation of the TDFF laser is achieved with the incorporation of a single modemultimode-single mode (SMS) interferometer in the laser cavity. The simple SMS interferometer is fabricated using the combination of two-mode step index fiber and single-mode fiber. With this proposed design, as many as eight stable laser lines are experimentally demonstrated. Moreover, when a tunable bandpass filter is inserted in the laser cavity, a dual-wavelength TDFF laser can be achieved in a 1.5-µm region. By heterodyning the dual-wavelength laser, simulation results suggest that the generated microwave signals can be tuned from 105.678 to 106.524 GHz with a constant step of ∼0.14 GHz. The presented photonics-based microwave generation method could provide alternative solution for 5G signal sources in 100-GHz region

A Microwave Signal Generation Technique Based on Brillouin-Erbium Fiber Laser

An all-optical microwave signal generator based on multiwavelength Brillouin-Erbium fiber laser (MBEFL) is proposed. The MBEFL unit is designed at fixed wavelength spacing of 0.084 nm, which corresponds to ~10 GHz carrier signal. The underlying mechanism MBEFL unit is by recycling the backscattered Stokes waves into the cavity to generate higher-order Stokes waves. Heterodyning process is then applied to the Brillouin pump (BP) consisted of first-order Brillouin Stokes (BS1) (0.084 nm spacing) and second-order Brillouin Stokes (BS2) (0.168 nm spacing) signals by using a photodetector (PD). The heterodyned outputs are microwave signals at the frequencies of 10.56 GHz and 21.2 GHz, relative to first order and second order Stokes waves, respectively. These microwave signals are experimentally achieved by controlling the EDF pump power where the EDF pump power can be as low as 20 mW

Bebe sdn. bhd. / Adila Ahmad Nazri...[et al.]

Bebe Sdn Bhd is a company that fully owned and managed by bumiputera. The company is headquartered in Shah Alam, Selangor. The company has been establised in the first quarter of 2015 and responsible for manufacturing of large scale of baby products. The existence of the company was approved and certified by Companies Commission of Malaysia (SSM). Bebe Sdn Bhd is a brand new company which has a speciality in producing and inventing different concept of baby product in the market based on latest wishes and trends alongside some user-friendly features. As the company has acquired more knowledges and experiences in this particular filed, Bebe has recognized and discovered the fact that most of the parents are hoping to give their best in many aspects for their children and definitely baby nutrition formula is not excluded in this case. The company is devoting more on services and quality of the products. The products are offered at affordable price and guaranteed with high quality products with some special features.The new concept of this products with new technology and user friendly product are highly believed to give customer's satisfaction to the maximum. The significant reason of choosing Shah Alam as our operating location is because of the middle to high income groups among Shah Alam's residents whichmay give better opportunity to dominate the market. We are starting the business with the total capital of RM250,000 and all of the partners are contributing RM60.000. We have six workers that is general manager, administration manager, operational manager, marketing manager, financial manager, and one from the operational department. Our market target of customers' characteristic is more focusing on medium to high income groups. However, the product is still considered and offered at affordable price since we also introduce the products to rural areas that have majority of low income group

Determinants of electronic commerce adoption: Case study among Small and Medium Enterprise (SME) in Klang Valley / Nur Atiqah Zainuddin … [et al.]

Nowdays, electronic commerce or e-commerce is the most important tool in business market especially in digital online marketing. It‘s create more competitive marketing among the business around the world and focusing on Small Medium Enterprise formerly SME. In Malaysia, e-commerce is among the tool use by SME with the role to expand their business that can be reachable by customers. The purpose of this study is to determine the factors affecting adoption of e-commerce by SME in Klang Valley and to identify the most influential factor on e-commerce adoption. A conceptual framework comprises of five factors that are relative advantage, compatibility, complexity, top management support and knowledge and resources constraint is being taken as variables for research. Multiple regression analysis generated is being carried out to test hypothesis and to establish the causal effect of relative advantage, compatibility, complexity, top management support and knowledge and resources constraint towards adoption of e-commerce. The result shows that relative advantage, compatibility, and top management support and knowledge have significant and positive impact on adoption of e-commerce. Therefore this study concluded that relative advantage, compatibility, and top management support and knowledge would increase adoption of e-commerce among SME. Therefore, the government should take initiatives and pay more attention to promote e-commerce among SME because SME has potential market growth and high contribution for economic development in Malaysia

Mobile and education

Mobile and education is an essential thing in this century. This paper examines issues or problems with the current way in mobile and education. The issues show almost all of the students who study online are using their mobile devices, especially because of the current situation of covid-19. Furthermore, this paper shows that the implementation of mobile phones and education can be used for students. The challenge for mobile learning according to trends because technology will change from time to time. Is mobile education a new form of distance education systems, which is characterized by the separation of lecturers for students spatially and temporally, and mobile learning a new language is a term that refers to the use of portable devices in the education process? This term focuses on using available technology with wireless communications to deliver information outside of the classroom, where he found this method to fit changing circumstances and the incident education process affected by the phenomenon of globalization. This can be achieved by using mobile and portable devices such as mobile phones Cell Phones digital assistant’s PDA are computers Handheld phones and computers Portable Computers personal computers and small Tablet PCs on all be equipped with technologies connect various wireless and wired alike which provides ease of information exchange between the students themselves on the one hand, and between students and lecturer on the other