39,299 research outputs found
Phase sensitive amplifiers for regeneration of phase encoded optical signal formats
We discuss the application of phase sensitive fiber optical parametric devices for the regenerative processing of high baud rate optical signals. We present recent advances in phase-sensitive amplification technology and its application to the regeneration of phase-encoded signals. By combining four wave mixing based parametric effects in highly nonlinear optical fibers and injection locking assisted synchronisation of multiple coherent lasers, we demonstrate how it possible to derive phase regeneration in signals with more than two levels of phase encoding
Performance of multichannel fiber optic parametric amplifier
Optical networks have a significant role to play in the present and future global
telecommunication networking scenario due to the increasing demand for larger
transmission capacity. In fiber optic communication systems, Dense Wavelength
Division Multiplexing (DWDM) is very popular in which multiple optical signals at
various wavelengths are combined and transmitted through a single fiber. DWDM
technology provides a cost effective deployment strategy. One of the key components in
DWDM system is an optical amplifier. Fiber optical parametric amplifier (FOPA) can
be used for several signal processing application including optical amplification, phase
conjugate and wavelength conversion. FOPA operate based on a fiber nonlinearity
known as four wave mixing (FWM). Fiber optical parametric amplifiers are based on
the third-order susceptibility of the glasses making up the fiber core. It happens when at
least two waves with the different frequencies co-propagate in the fiber. In this
simulation is to show the ability of a single pump parametric amplifier in the eight
channels DWDM transmission system and performance of FOPA in order to ensure
higher level of amplification coped with less amplifier produced signal impairments.
The simulation were done by software OptiSystem 13, the fiber optical amplifier is
perform by simulation of 10 Gbit/s each channel. Furthermore NRZ encoding
technique, intensity OOK modulation format has been used in this simulation. The
frequencies of channel carrier was chooses in the region from 193.1 THz to 193.8 THz.
Eight modulated signal are transmitter over 220 km span long single mode fiber. The
single pump combination with four signal radio frequency, 180 MHz, 420 MHz, 1.087
GHz and 2.133 GHz are used to show higher level of amplification and mitigating the
impact of simulated Brillouin scattering. As a result, the maximum 22.134 dB gain and
lower noise figure 2.84 dB is achieved
Introduction to the issue on novel and specialty fibers
The fiber optical communication revolution has been fueled by well publicized and relentless improvements of transmission fiber. Since the demonstration of the first low-loss optical fiber in 1972, there has been a continual stream of technology improvements designed to reduce impairments due to propagation loss and pulse dispersion. This steam of fiber technology has led the industry from multimode fiber operated at 800 nm, to standard single-mode fiber used at 1310 nm, then on to transmission fibers that now have attributes tuned for particular applications such as terrestrial or submarine transmission. There is every reason to believe that advances in technology will continue at the accelerating pace we have seen in the past decade, adding to the family of available transmission fibers. The special issue is dedicated to the increasing family of specialty fibers, and includes exciting papers on fibers for gratings and a unique amplification fiber. Fibers for specialized transmission spanning a broad range of applications are also described in three important articles. As is appreciated by all optical scientists, progress can be made only as quickly as one can improve measurement capabilities, so the issue includes two excellent papers dealing with the important measurement of chromatic dispersion.We hope that you enjoy the papers of this issue as much as we the editors have enjoyed reading and reviewing them
Kompetensi guru dalam pengajaran amali reka bentuk dan teknologi di Sekolah Rendah Daerah Batu Pahat
Kompetensi bermaksud kemampuan atau kecekapan seseorang individu dalam
melakukan sesuatu tugasan. Kompetensi juga merujuk kepada kemampuan
seseorang dalam melaksanakan sesuatu yang diperolehi melalui pendidikan dan
juga merujuk kepada prestasi dan perbuatan yang rasional untuk memenuhi
spesifikasi tertentu di dalam pelaksanaan tugas-tugas pendidikan. Objektif
kajian ini dijalankan adalah untuk mengenalpasti tahap kompetensi guru
terhadap pengajaran amali Reka Bentuk dan Teknologi di Sekolah Rendah
Daerah Batu Pahat. Kajian ini berbentuk tinjauan deskriptif yang menggunakan
borang soal selidik sebagai instrumen kajian. Borang soal selidik yang dibina
adalah berdasarkan kepada tiga elemen iaitu elemen pengetahuan, kemahiran
dan sikap. Seramai 118 orang guru yang mengajar mata pelajaran ini telah
terlibat sebagai responden. Data yang dikumpulkan telah dianalisis dengan
menggunakan perisian Statistical Package for Social Science (SPSS) versi 19
yang melibatkan statistik skor min dan ujian-T tidak bersandar. Hasil dapatan
kajian yang diperolehi menunjukkan guru-guru Reka Bentuk dan Teknoogi
mempunyai tahap kompetensi yang tinggi terhadap proses pengajaran amali
iaitu skor min yang diperolehi pada elemen pengetahuan adalah 4.23, elemen
kemahiran adalah 4.30, dan elemen sikap adalah 4.47. Dapatan kajian juga
menunjukkan tidak terdapat perbezaan yang signifikan terhadap tahap
kompetensi berdasarkan jantina guru lelaki dan guru perempuan dengan nilai
sigifikan melebihi 0.05 iaitu sebanyak 0.059. Beberapa cadangan untuk
penambahbaikan juga dikemukan dalam kajian ini. Hasil dari dapatan kajian ini
dapat digunakan sebagai cadangan garis panduan kepada guru-guru Reka
Bentuk dan Teknologi untuk mencapai Standard Kompetensi Guru
Analyses of 100 Gbps Coherent System Performances
This paper presents the results of laboratory and field testing of coherent 100 Gbps system with DP-QPSK modulation. Several measurements were performed including power budget, nonlinear threshold, spectrum filtration, constellation diagram, interoperability with 10 Gbps lambdas and dispersion compensation type impact. Field tests addressed transmission of 100 Gbps signal as an Alien Wavelength through multivendor network, influence of photonic service parallel to 100 Gbps signal and performance of 100 Gbps system over single fiber bidirectional transmission lines. 100 Gbps system has been found extremely resilient to most classical impairments thanks to advances error coding and compatible with standard 10 Gbps NRZ lambdas and any type of dispersion compensation. The system was also working over single fiber bidirectional lines and in parallel with Photonic Service of time transfer. The paper also shows recent results of single hop test with 100 Gbps system in laboratory environment
Amplified Dispersive Fourier-Transform Imaging for Ultrafast Displacement Sensing and Barcode Reading
Dispersive Fourier transformation is a powerful technique in which the
spectrum of an optical pulse is mapped into a time-domain waveform using
chromatic dispersion. It replaces a diffraction grating and detector array with
a dispersive fiber and single photodetector. This simplifies the system and,
more importantly, enables fast real-time measurements. Here we describe a novel
ultrafast barcode reader and displacement sensor that employs
internally-amplified dispersive Fourier transformation. This technique
amplifies and simultaneously maps the spectrally encoded barcode into a
temporal waveform. It achieves a record acquisition speed of 25 MHz -- four
orders of magnitude faster than the current state-of-the-art.Comment: Submitted to a journa
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