50 cm of Zirconia, Bismuth and Silica Erbium-doped Fibers for Double-pass Amplification with a Broadband Mirror

Erbium-doped fiber amplifiers (EDFAs) have saturated the technological market but are still widely used in high-speed and long-distance communication systems. To overcome EDFA saturation and limitations, its erbium-doped fiber is co-doped with other materials such as zirconia and bismuth. This article demonstrates and compares the performance using three different fibers as the gain medium for zirconia-erbium-doped fibers (Zr-EDF), bismuth-erbium-doped fibers (Bi-EDF), and commercial silicaerbium-doped fibers (Si- EDF). The optical amplifier was configured with a double-pass amplification system, with a broadband mirror at the end of its configuration to allow double-pass operation in the system. The important parameters in amplifiers such as optical properties, optical amplification and noise values were also examined and discussed. All three fibers were 0.5 m long and entered with different input signals: 30 dBm for low input and 10 dBm for high input. Zr-EDF turned out to be the most relevant optical amplifier as it had the highest optical gain, longest transmission distance, highest average flatness gain with minimal jitter, and relevant noise figures suitable for the latest communication technology

Wireless hand motion controlled robotic arm using flex sensors

In today's world, in almost all industries, much of the work is performed by robots or robotic arms with varying degrees of freedom (DOF) as necessary. The aim of this study is to adjust the perception of remote controls for manually controlled robotic-arm operation. This paper offers a way of thinking and a way to eradicate the keys, joysticks and replace them with some of the more intuitive strategy that is to operate the full robotic arm by hand movements operators. The robotic arm is constructed in such a way that it consists of two movable fingers and other movement, which is, a spreading elbow and the up down movement. The robotic arm is designed to mimic the motions of human hands using a hand glove. The hand glove consists of 3 flex sensors for controlling the motions of the finger, the elbow, and other movements. Servo motors are the actuators used by the robotic arm. The proposed electronics device recognizes a basic hand gesture that will be made in real lifetime and will relay valued signals wirelessly through the RF module

Modelling base electricity tariff under the Malaysia incentive-based regulation framework using system dynamics

In the context of a single buyer (SB) electricity market, this study provides an electricity tariff model developed using system dynamics (SD). Using data from the Malaysian electricity supply industry (MESI), the model was developed with the intent of evaluating the influence of load variation on Malaysia’s base electricity tariff. Given that Malaysia’s electricity demand has increased significantly over the past few years in unison with the country’s economic growth and modernization, this model is developed to investigate the relationship between the two. Moreover, the lack of a comprehensive MESI upstream market model that can monitor this issue was the impetus for this research. This study employed an SD approach, as it is a well-known technique for simulating complex systems and analyzing the existing dynamism between each variable and each system. This model can be a valuable tool for developing an electrical tariff model. Findings revealed that the base electricity pricing on the MESI upstream market is affected by load growth variation during the 30-year time. Since new power sources are needed to meet demand, the tariff becomes more expensive as the load increases. This model may benefit the utility or generating company plan for future generation

Comparative Analysis between Dynamic Voltage Restorer and PWM-Switched Autotransformer in Voltage Sag Mitigation

This research aims to address the problem of voltage sag, which is a significant power quality issue in power systems. Voltage sag can lead to power transmission and distribution line tripping and cause damage to electrical equipment. Various voltage sag mitigation devices have been developed to reduce the impact of voltage sag. In this study, we analyze the effectiveness of three types of voltage sag mitigation devices under different voltage sag conditions: three-phase fault, multi-phase fault, and energizing transformer inrush current. The three types of mitigations analyzed are Dynamic Voltage Restorer (DVR) with Park's transformation, DVR with Artificial Neural Network (ANN) controller, and PWM-switched autotransformer with Proportional-Integral (PI) controller. The simulation results using MATLAB demonstrate that all voltage sag conditions have been mitigated except for PWM-switched autotransformer during voltage sag caused by energizing transformer inrush current due to limitations of the PI controller scheme. Based on the analysis of input and output voltage waveforms, three-phase voltage magnitude before and after mitigation, and Total Harmonic Distortion (THD) value after mitigation, DVR with ANN controller is identified as the most effective voltage sag mitigation device, followed by DVR with Park's transformation and PWM-switched autotransformer

Comparative Analysis between Dynamic Voltage Restorer and PWM-Switched Autotransformer in Voltage Sag Mitigation

This research aims to address the problem of voltage sag, which is a significant power quality issue in power systems. Voltage sag can lead to power transmission and distribution line tripping and cause damage to electrical equipment. Various voltage sag mitigation devices have been developed to reduce the impact of voltage sag. In this study, we analyze the effectiveness of three types of voltage sag mitigation devices under different voltage sag conditions: three-phase fault, multi-phase fault, and energizing transformer inrush current. The three types of mitigations analyzed are Dynamic Voltage Restorer (DVR) with Park's transformation, DVR with Artificial Neural Network (ANN) controller, and PWM-switched autotransformer with Proportional-Integral (PI) controller. The simulation results using MATLAB demonstrate that all voltage sag conditions have been mitigated except for PWM-switched autotransformer during voltage sag caused by energizing transformer inrush current due to limitations of the PI controller scheme. Based on the analysis of input and output voltage waveforms, three-phase voltage magnitude before and after mitigation, and Total Harmonic Distortion (THD) value after mitigation, DVR with ANN controller is identified as the most effective voltage sag mitigation device, followed by DVR with Park's transformation and PWM-switched autotransformer

Ultrafast soliton mode-locked Zirconia-based Erbium-doped fiber laser with carbon nanotubes saturable absorber

Ultrafast soliton mode-locked fiber laser was successfully generated in zirconia-yttria-alumina (Zr-Y-Al) co-doped erbium-doped fiber laser cavity using a single-wall carbon nanotubes (SWCNTs) as saturable absorber. The laser cavity was 11.5 m long with the group delay dispersion of -0.04 ps(2). The laser generates soliton pulse train with a center wavelength and 3 dB bandwidth of 1564.2 nm and 3.8 nm, respectively at pump power of 92 mW. Meanwhile, the repetition rate, pulse duration and pulse energy were 17.7 MHz, 770 fs and 51.4 nJ

Picoseconds Dark Pulse Zirconia-Yttria-Aluminium-Erbium-doped Fiber Laser

A 3.4 picoseconds dark pulse fiber laser was successfully generated using Zirconia-YttriaAlumina-Erbium-doped fiber laser (Zr-EDF) cavity with graphene oxide as saturable absorber.The laser cavity was 11.5 m long with the group delay dispersion of -0.04 ps2. Themultiwavelength optical spectrum provides 1 MHz repetition rate and 67.8 dB optical signal tonoise, defines the high stability of the dark pulse. A strong nonlinearity and high birefringenceof the Zr-EDF and GOSA cause the pulse turn down to dark region. An ultrafast dark pulse is demand due to low interference and excellent stability in the existence of noise that are requiredfor high efficiency and accuracy demanding by biomedical devices

IoT Air Pollution Monitoring System

Air quality must be monitored and kept under control for a better future and a healthy life. Here we propose an air quality as well as an air pollution monitoring system enable us to monitor and control the quality of live air through IoT in specific areas. This system used sensor to constantly detect harmful gases in the air. System also maintains the air level measurement and reports it via IoT to the Blynk application. The sensor interacts with the microcontroller to process the data and transmit through the internet. This allows authorities to monitor and take action against air pollution in various areas. Authorities can also monitor air pollution in the vicinity of school, and hospital. Where the system detects the air quality problem, the authorities are alerted so they can take control measure. The main component of IoT air pollution monitoring system is Arduino Mega 2560 as a microcontroller. The input used is MQ135 sensor and MQ-7 to detect contaminated air. This sensor will place at a higher place to easily detect the pollution air. There are 3 output are LEDs, Wi-Fi module, and LCD display. This probably uses a LED and buzzer as an indicator on this system to show the system is running. The LCD is used to show the air concentration either the safe air or not. If the air is polluted, the system will bring alerts to nearby areas. This Wi-Fi module helps a nearby people to know information about air concentration. This surely can make they feel safe because they can know about current air concentration

Metal Oxide Coated Optical Fiber for Humidity Sensing Application: A Review

Humidity measurement in biomedicals, industry and electronic manufacturing applications needs an accurate and fast measurement of relative humidity by the sensor. In recent years, electronic sensors are utilized in the market, but optical humidity sensors provide several advantages over it. This paper reports the classification of optical fiber humidity sensors based on their working principles, such as fiber Bragg gratings, interferometers, and resonators. Along with the mentioned optical fiber structures, their fabrication process, equipment required for humidity sensing and the coating technique used are explained in this review. Recently, metal oxide semiconductors have been widely used as sensing material, specifically in humidity sensor applications. Thus, this paper explores optical fiber humidity sensors based on the three working principles mentioned, all of which incorporate metal oxide coatings. This review reveals that the most commonly used metal oxide for optical fiber humidity sensing is graphene oxide. This is because graphene oxide offers high sensitivity, fast response and recovery time over the other types of metal oxide. A large number of oxygen-containing groups on the surface and edge of graphene oxide also contribute to humidity sensing performance since it can permeate and absorb more water molecules. The use of hybrid nanomaterials is recently discovered and their potential as emerging coating material for optical applications are not fully exploited yet. Thus, there is still an opportunity for improvement in terms of sensitivity, response and recovery time in the context of optical fiber humidity sensor

Erbium-zirconia-yttria-aluminum co-doped fiber for amplifier and nanomaterial based ultrafast laser applications / Arni Munira Markom

The tremendous growth in telecommunications traffics increased the demand for very high speed, large capacity and long-haul transmission systems. Therefore, a new optical amplifier is required to overcome the limitations of conventional erbium-doped fiber amplifier. Besides optical amplifier, another interest is on pulsed lasers. Pulsed lasers have expanded an incredible attention in recent years as a possible replacement to high-cost and bulk solid state lasers especially for ultrafast technology with pulse duration down to the femtosecond and attosecond region which led to many diverse applications. In this work, a new Zirconia-Yttria-Aluminum co-doped Erbium-doped fiber (Zr-EDF) was investigated as gain medium for amplifier and pulsed laser applications. The fiber is heavily doped with erbium concentration with absorption pump power around 80 dB/m at 980 nm and was fabricated by using modified chemical vapour deposition (MCVD) process. For amplifier application, this fiber can be used to obtain an efficient gain and noise figure for both single- and double-pass configurations. For instance, at optimum length of 1 m for double pass amplifier, the highest gain of 40.3 dB was achieved at 1560 nm with noise figure less than 6 dB for the specific region. Moreover, a high flat-gain of 38 dB with gain fluctuation of ± 1.5 dB was successfully obtained within 1530 to 1565 nm wavelength. The new Zr-EDFA also performed better compared to the amplifiers configured with the previous Zr-EDF with a lower erbium concentration, conventional bismuth-based EDF (Bi-EDF) and the commercial silica-based EDF (Si-EDF). Pulsed Zr-EDF lasers (Zr-EDFLs) were also demonstrated by using various passive methods. A bright and dark pulse Zr-EDFL were delivered by using nonlinear polarization rotation (NPR) technique to generate dual-wavelength with pulse duration of 27 ns and repetition rate of 14.1 MHz. Q-switched pulsed laser was realized by using thulium-doped fiber (TDF) as solid state saturable absorber (SA) fiber. Bright solitons were also obtained by using high nonlinearity SAs of carbon nanotubes (CNTs) and graphene oxide with the generation of ultrashort pulse duration of 770 fs and 600 fs, respectively. Finally, mode-locked Zr-EDFLs operating in dark pulse regime were successfully demonstrated using three types 2D nanomaterials SAs; graphene oxide, graphene film and black phosphorus as the mode-locker