Single Stage C-Band Erbium-Doped Fiber Amplifier (EDFA) Development and Performance Evaluation

In this work, a single-stage C-band erbium-doped fiber amplifier (EDFA) has been constructed and characterized. Gain (G) and noise figure (NF) measurements collected for the C-band EDFA as a function of wavelength (1528.8 to 1562.3 nm) and laser pump powers are discussed. Further, the EDFA conversion efficiency (CE) as a function of laser pump powers is presented. Simplified mathematical expressions for the EDFA gain, NF, and CE are provided. The C-band EDFA signal gain remained flat in the spectral region 1539 to 1562 nm. Moreover, the C-band EDFA NF increased with wavelength and decreased with the 1480 nm laser pump powers. Additionally, the C-band EDFA maximum achieved conversion efficiency and signal gain is 22.64% at P1=19.49 mW and 22.6 dB at 1531.1 nm, respectively.

Design of S-Band Antenna With L-Shaped Slits on Rectangular Patch With Defected Ground Structure

Monopole L-shaped slits are embedded on rectangular patch antenna is designed for S-band applications. The proposed antenna is a square patch radiator with four L-shaped slits are presented. The proposed antenna radiates at 3GHz resonance frequency with bandwidth of 1.9GHz and -26.4dB return loss. The impedance bandwidth is enhanced 62.7% with proposed antenna model. The proposed L-shaped slit patch antenna is small in size and compact. The radiation pattern is presented in the results and it works at S-band applications.

Generation of Patterns From Concentric Ring Arrays With Dipoles and Waveguides

Radiation patterns are produced from concentric ring arrays by using practical elements, such as dipoles and waveguides which is presented in this article. Ring arrays, which produces high sidelobes, create electromagnetic interference (EMI) problems. To overcome this problem, analysis and synthesis is carried out and generates the directional patterns of concentric ring arrays using practical radiators. The directivity is observed for concentric dipole ring arrays and concentric waveguide ring arrays is 72.21 dB. The comparative data is presented in the result.

Measurement and Monitoring System With Real Time Data Logging Based on Microcontroller

This article presents a microcontroller-based system for measurement and monitoring voltage of a three-phase electrical system with real-time data logging abilities. The proposed system uses voltage signals and time data as input. The output is an LCD and data files. The system accurately records abnormal voltage variations which have occurred on the system. A PC software is developed to receive and save data in two spreadsheet files through a serial port. Ihe log file contains the measured voltage, which is recorded periodically with a predefined time interval, and the second file contains the type of the fault. The proposed system is first simulated by ISIS-Proteus and then realized and implemented on an electronic board. It is beneficial to make detailed, scientific judgments and analysis for the voltage system to be supplied to a load. Because of the very simple circuit, it finds applications in industrial facilities. It is also useful in applying final circuits for both investigation and monitoring purposes.

Qualitative Analysis of IT/IS Evaluation Practices in Private Organisations in Saudi Arabia

Many studies have been carried out on information technology/information systems (IT/IS) in the Western world, but little research has been conducted in the Saudi private sector. This study has been conducted to identify and examine the IT/IS evaluation processes employed in the Saudi private sector and any factors that hinder such organisations from evaluating their systems effectively. This article concentrates on the results of those interviews. Numerous studies have been conducted on the mechanisms of IT/IS evaluation techniques and the factors affecting their implementation, but there are very few studies in this field in Saudi Arabia, and they are generally sections of other main studies about IT implementation, use, and investment. This article aims to identify means of evaluating IT/IS in the private sector. 30 IT managers in private-sector companies were randomly selected from the list of top companies issued by the Council of Saudi Chambers of Commerce in the Kingdom of Saudi Arabia.

Plastic Diffraction-Limited Wide-Angle Air-Spaced Cooke Triplet Lens Designs for SWIR Imaging Applications: Image Quality Analysis Using Zemax®

In this study, the optical performance of plastic (acrylic-polycarbonate-acrylic, acrylic-polystyrene-acrylic, PMMA-polycarbonate-PMMA, and PMMA-polystyrene-PMMA) diffraction-limited air-spaced Cooke triplet lens designs optimized for the spectral range 0.995 to 1.01 µm are presented. Comparing the acrylic-polycarbonate-acrylic air-spaced Cooke triplet lens design with the other three plastic lens designs, the obtained results indicate that the acrylic-polycarbonate-acrylic design can achieve the best image quality performance at 50% contrast 56 cycles/mm and Strehl ratio= 0.989 for the on-axis field-of-view (FOV= 0°). Furthermore, over the temperature range 18.30 to 22.25 °C and over +12° FOV the acrylic-polycarbonate-acrylic air-spaced Cooke triplet lens design performance remained diffraction-limited (Strehl ratio < 0.8). The low cost and the light weight of plastic optical components makes them attractive for several industrial applications. As an example, plastic lenses are incorporated into cell phone cameras and LED collimation optics.

45.5X Infinity Corrected Schwarzschild Microscope Objective Lens Design

In this article, the design of a 45.5X (numerical aperture (NA) =0.5) infinity corrected, or infinite conjugate, Schwarzschild reflective microscope objective lens is discussed. Fast Fourier transform modulation transfer function (FFT MTF= 568.4 lines/mm at 50% contrast for the on-axis field-of-view), root-mean-square wavefront error (RMS WFE= 0.024 waves at 700 nm), point spread function (PSF, Strehl ratio= 0.972), encircled energy (0.88 µm spot radius at 80% fraction of enclosed energy), optical path difference (OPD=-0.644 waves) and Seidel coefficients calculated with Zemax® are provided to show that the design is diffraction-limited and aberration-free. Furthermore, formulas expressing the relationship between the parameters of the two spherical mirrors and the Schwarzschild objective lens focal length are given. In addition, tolerance and sensitivity analysis for the Schwarzschild objective lens, two spherical mirrors indicate that tilting the concave mirror (or secondary mirror) has a higher impact on the modulation transfer function values than tilts introduced by the convex mirror (or primary mirror). Finally, the performed tolerance and sensitivity analysis on the lens design suggests that decentering any of the mirrors by the same distance has the same effect on the modulation transfer function values.

Error Estimations for Flow Characterization With Numerical and Analytical Solutions

Use of radial basis functions(RBFs) in the numerical solution of partial differential equations has gained popularity as it is meshless and can readily be extended to multi-dimensional problems. RBFs have been used in different context and emerged as a potential alternative for numerical solution of PDEs. In this article, a Flow Between Parallel Plates problem was solved using a Multiquadric Radial Basis Function Collocation Method (MQ-RBFCM), then, the results were compared with the analytic ones and the root mean square of the errors between the model and analytic results were calculated. Numerical results are presented for 5 different cases, where the number of inputs or definitions are increased to see whether changing the number of points makes the results better or not. Also, the absolute errors between the results were calculated to have a 3D model of the error rates and this has proven for which cases the MQ-RBFCM are better. As a result, RBF is shown to produce accurate results while requiring a much-reduced effort in problem preparation in comparison to traditional numerical methods.

The Challenge of Developing Primary Standards Mixtures of Carbon Dioxide at Atmospheric Levels to Establish Traceability to GHG Monitoring Analysis

This article describes how in recent years the need for the quality control, reliability and traceability of analytical results has been strongly emphasised. The National Institute of Metrology, Quality and Technology, is involved in improving calibration and measurement capabilities to provide high confidence level in accordance with the latest regulation regarding greenhouse gases standards. This article describes the gravimetric production of certified gaseous reference materials of carbon dioxide in atmospheric synthetic air that are used to monitor its concentration in the atmosphere. Considering the contributions from gravimetry preparation and its verification analysis by cavity ringdown system (CRDS) the relative expanded uncertainty of the standard mixture of carbon dioxide was lower than 0.5% for the range studied from 370 to 550 μmol/mol, which is comparable to the average of 0,25% relative uncertainties presented on international standards mixtures.

Improving Interferometry Instrumentation by Mixing Stereoscopy for 2π Ambiguity Solving

Phase measurements obtained by high-coherence interferometry are restricted by the 2π ambiguity to height differences smaller than λ/2. A further restriction considers linear and nonlinear aberrations evolving in most interferometric systems due to the CCD-type array detectors. The authors present a new method to overcome the 2π ambiguity in interferometry when using a stereoscopic approach. In this method, a reconstructed wavefront reflected from an object was propagated into two different angles to obtain two different images of the object. These two different images were subsequently processed by stereo algorithms to resolve the 2π ambiguity. Such a method of wavefront propagation may enable several applications such as focusing and resolving the 2π ambiguity, as described in the article.