Design And Development Of Semiconductor Based And Fiber Laser Based Optical Transmitter

This thesis presents the research works on development, characterization, application and analysis of semiconductor based and fiber laser based optical transmitter. Semiconductor laser is the most widely used in the optical communication system. This is mainly because of the compact size, weight and simplicity of modulation scheme. Laser diode is used in developing the optical transmitter and the application in the optical communication. The function of the optical transmitter is to convert the electric signal into optical signal and thus the optical transmitter is also called Electric to optical (E/O) converter. There are two approaches used in this thesis : simulation and experiment. Simulation is designed to check and determine the functionality of the designed circuit

Intra-cavity spectroscopy using amplified spontaneous emission in fiber lasers

Fiber laser sources offer interesting possibilities for gas sensors since they can operate over an extended wavelength range, encompassing the near-IR absorption lines of a number of important gases but a major problem is that overtone absorption lines of gases in the near-IR are relatively weak. In order to enhance sensitivity, we present here a simple method of intra-cavity absorption spectroscopy (ICAS) which makes use of the amplified spontaneous emission (ASE) already present within a fiber laser cavity. The ASE also provides a convenient broadband source for the simultaneous interrogation of several gases within the gain-bandwidth of the fiber laser. The key principle is based on adjusting the cavity attenuation to select an appropriate inversion level where the fiber gain curve is flat. Under this condition, the ASE undergoes multiple circulations within the fiber laser cavity, enhancing the effective path-length of a gas cell placed within the laser cavity. A theoretical model of system operation is given and we have experimentally demonstrated the principle of operation with acetylene and carbon dioxide using a simple erbium fiber laser system containing a 6 cm path-length, fiber coupled, intra-cavity, micro-optic gas cell. We have experimentally simultaneously observed 16 absorption lines for 1% acetylene gas in the 1530 nm region and detected the very weak carbon dioxide lines in this same wavelength region. A path length enhancement of in the linear regime has been demonstrated transforming the 6 cm micro-optic cell into an effective path length of m. We also demonstrate how the enhancement factor may be calibrated by use of a simple fiber-optic interferometer. Apart from the OSA, all components are inexpensive and the system is very simple to construct and operate

CWDM Network Design 8 channel using Hybrid Amplifier SOA-EDFA

In this experiment we propose and demonstrate a CWDM transmission system using hybrid amplifiers SOA-EDFA. A new hybrid two-stage in the system of optical fiber amplifier for coarse wavelength division multiplexing (CWDM) network is studied. The hybrid amplifier is a cascaded semiconductor optical amplifier (SOA) and erbium- doped fiber amplifiers (EDFA) which provide a nearly flat gain over 80 nm. The hybrid amplifier has been modeled using a OptiSystem version 9 by Optiwave modeling tool on a CWDM transmission system which consisting of two spans of 100 km

The Assessment Characteristic of ZnO Material for Optical Sensing Layer Probe Using Average Scanning of FFT (ASFFT) Method

ZnO material characterization was done to be used as optical probes from the plastic optical fiber. Characterization of ZnO materials by processing data obtained from scanning probe microscope (SPM) NTEGRA-AURA. The obtained data is in the form of images with different distance observations. It will be processed by 11 simulated images of proceeds image analysis (IA Analysis). Methodology of data processing is using average scanning Fast Fourier Transformation (ASFFT). This method consists of five characterization data processing techniques, i.e., power spectral density techniques, power spectral technique, magnitude spectrum technique, square root magnitude spectrum techniques and logarithmic spectrum techniques. The goal of average scanning FFT is determines a value of special characterization, because the result of surface morphology from SPM images cannot give exact information . Each techniques in this method will be used to see the details of each ZnO layer surface morphology of in units of frequency or frequency. The observation study of ZnO characterization is made by Atomic Force Microscopy without doing renovation materials. The treatment material as a layer probe of plastic optical fiber sensor was studied for detecting various chemical vapor and air pressure. Based on the detection method called interferometric Fabry – Perot, Plastic Optical Fiber probes will detect the changes of ZnO layer refractive index causes by environments

Optimum Efficiency Analysis of Ecofriendly WDM-POF Optical Coupler

This chapter was presented to promote the development of Wavelength Division Multiplexing, WDM networking system based on Polymer Optical Fiber (POF). 1 × 3 POF coupler has been fully utilized to couple the WDM optical signals. An optimum efficiency analysis and mathematical modeling has been conducted to produce an effective device to be integrated into WDM-POF system. But despite its high speed data transmission feature, optical fiber technology remains an expensive option in optical network, although the installation costs associated with fiber through the transmission network can be minimized through the fabrication of 1 × 3 POF coupler. The objective of this chapter is identifying the differences in factors affecting the output power of the POF 1 × 3 coupling. It is then able to develop an efficient WDM-POF network system with high output power at a minimal cost. Several measurements using a power meter record performance and analysis device losses and power outputs. The demultiplexer efficiency is approximately 70%. Demultiplexer fabrication is easy with color and epoxy filters, although for some parts it requires careful attention. The output shows that Ecofriendly WDM-POF Optical Coupler can be used as one of the low-cost media for home networking and automotive applications

Assessment of Student Program Outcomes through a Comprehensive Exit Strategy

AbstractChoosing methods to assess student program outcomes is a matter of balancing best practices against the constraints imposed by the respective education authorities mainly the Engineering Accreditation Council (EAC) for engineering degrees offered by institutions of higher education in Malaysia. Methods that directly measure student learning and yield the most rigorous results are usually the most time consuming and may require the expertise of educational researchers or outside consultants. Currently, the Department of Electrical, Electronics and Systems Engineering at UKM use their classroom and existing grading practices to collect data that will contribute to assess student learning directly, but this requires extra time and effort. In addition, mechanisms to adequately report the findings need to be properly implemented. Another mechanism that could be used to assess student program outcomes is through a thoroughly designed student exit strategy. The exit strategy implemented this academic year involves two parts; exit survey and exit test. This is a Continuous Quality Improvement (CQI) effort done since the past two academic years that enables the department to assess student program outcomes directly and indirectly in one approach. The exit strategy has proven successful as a valid measurement of student program outcomes. The exit strategy which combines both direct and indirect assessment forms a comprehensive and robust tool to effectively measure student program outcomes

Evaluation of Students’ Achievement in the Final Exam Questions for Microelectronic (KKKL3054) using the Rasch Model

AbstractThe assessment of the students in KKKL3054 Microelectronic includes PBL (20%), quizzes (10%), midterm exam (20%), tutorial (10%), and final exam (40%). In this paper, we discuss the performance of the students’ achievement in the final examination. By using the Rasch model, the students’ performance based on the difficulty level of each question, can be assessed. Each question is mapped to the number of students who are able to answer the question correctly. Results from the 17 students assessed, answering 15 questions of the final examination, showed that the distribution of the ability of each student answering questions from different levels of difficulty are fairly distributed. Findings from this evaluation can help us improve the course content as well as the course outcomes. We can conclude that by using the Rasch model, the ability of each student answering the final exam questions can be evaluated

A trail to milieu research methodology for application of implementation frameworks in manufacturing sector

The profusely used tools of operational management research in lean manufacturing context include roadmap, conceptual model, implementation frameworks, descriptive planning and assessment checklist. Out of these, an implementation framework development in lean manufacturing sector is common, but faces quandary regarding its development, consolidation and validation – thereby confirming the requirement of availability of succinct platform that aids in research methodology development. The aim of this research is to attain a clear research context, achieved accordingly by detailed literature review study that would subsequently aid in developing a generic research methodology design framework. Concomitant to it, the four layers, the layers of research onion were discussed; followed by selection of appropriate methods for development of research methodology in order to arrive at implementation frameworks. It was observed that for the methodology development, the philosophy of pragmatism is highly suitable, followed by abductive logic, in case of technique, mixed mode research is best, whereas in strategy selection, case study strategy is the most suitable due to its multi-functional ability of in-depth operational study. In addition to that, the mixed-mode approach carries the ability of comparative qualitative and quantitative research through longitudinal and cross-sectional case study respectively. Furthermore, the data collection processes were discussed in relevance to the research objective, which culminated in the formation of a detailed research methodology which has been divided into three major stages of research context and approach, framework development and validation, resulting in attaining implementation framework through literature review, longitudinal case study and cross-sectional case study respectively. The major strength and contribution of this research study is the development of one concise research methodology that is considered as the paradigm shift and a clear innovation towards this field