Fibre Bragg Grating Sensors An Introduction to Bragg gratings and interrogation techniques
|
|
- Andra Clarke
- 7 years ago
- Views:
Transcription
1 Fibre Bragg Grating Sensors An ntroduction to Bragg gratings and interrogation techniques Dr Crispin Doyle Senior Applications Engineer, Smart Fibres Ltd ) The Fibre Bragg Grating (FBG) There are many different types of Optical Fibre Sensor (OFS), working on many different principles: intensity modulation (e.g., microbending), interferometry, polarization effects, refractive index changes, reflectometry and so on. One relatively mature type which appears to be particularly attractive in many applications is the Fibre Bragg Grating (FBG). Bragg gratings are made by illuminating the core of a suitable optical fibre with a spatially-varying pattern of intense UV laser light. Short-wavelength (<300 nm) UV photons have sufficient energy to break the highly stable silicon-oxygen bonds, damaging the structure of the fibre and increasing its refractive index slightly. A periodic spatial variation in the intensity of UV light, caused by the interference of two coherent beams or a mask placed over the fibre, gives rise to a corresponding periodic variation in the refractive index of the fibre. This modified fibre serves as a wavelength selective mirror: light travelling down the fibre is partially reflected at each of the tiny index variations, but these reflections interfere destructively at most wavelengths and the light continues to propagate down the fibre uninterrupted. However, at one particular narrow range of wavelengths, constructive interference occurs and light is returned down the fibre. Maximum reflectivity occurs at the so-called Bragg wavelength λ Β, given by: λ Β =2n eff Λ (1) where n eff is the effective refractive index of the mode propagating in the fibre and Λ is the FBG period. Λ Figure 1. FBG, indicating core refractive index variations Equation (1) implies that the reflected wavelength λ Β is affected by any variation in the physical or mechanical properties of the grating region. For example, strain on the fibre alters Λ and n eff, via the stress-optic effect. Similarly, changes in temperature lead to changes in n eff via the thermo-optic effect and in an unconstrained fibre, Λ is influenced by thermal expansion or contraction. This situation is expressed in Equation 2, where the first term on the RHS gives the effect of strain on λ Β and the second describes the effect of temperature.
2 λ Β = λ Β (1-ρ α ) ε + λ Β (α+ξ) T (2) where λ Β is the change in Bragg wavelength, ρ α, α and ξ are respectively the photoelastic, thermal expansion and thermo-optic coefficients of the fibre, ε is the change of strain and T is the temperature change. For a typical grating written in a silica fibre and with λ B 1550 nm, sensitivities to strain and temperature are approximately 1.2 pm/µε and 10 pm/ C respectively. The FBG has certain useful characteristics. 1) The sensor is a modified fibre. t has the same size as the original fibre and can have virtually the same high strength. This is in marked contrast to many other types of optical fibre sensor which are either bigger, weaker or both. 2) Because information about the measurands is encoded in the wavelength of the reflected light, FBG sensors are immune to drifts and have no down-lead sensitivity. The responses to strain and temperature are linear and additive and the FBG itself requires no on-site calibration. 3) Multiple gratings can be combined in a single fibre by taking advantage of multiplexing techniques inspired by the telecommunications industry. This gives FBG sensor systems the important property of being able to simultaneously read large numbers of sensors on a very few fibres, leading to reduced cabling requirements and easier installation. 4) Temperature and strain can be measured with the same sensor. n practise, this property can be a two-edged sword. Accurate measurements of strain in the presence of significant temperature excursions require gratings to be deployed in pairs, one sensitive to temperature and strain, bonded securely to the structure of interest and one close to it but isolated from strain, responding to temperature only. n practise, this doubling-up of sensors is not too problematical because there are almost invariably spare FBG which a given unit can address, specifically for the purpose of temperature compensation. 2) FBG nterrogation To use an FBG as a sensor, it is illuminated by a light source with a broad spectrum and the reflected wavelength is measured and related to the local measurands of interest. Shifts in the Bragg wavelength can be monitored by any of the following techniques: An interferometer may be used to convert wavelength shifts into phase shifts, which can be detected by measuring variations in the light intensity as the path difference in the interferometer is varied. This technique potentially allows for very high sensitivity, but the equipment to do it is expensive and prone to environmental interference. No commercial equipment employs interferometry. A sloped optical filter, which may be another Bragg grating, can be used to convert wavelength shifts directly into intensity changes. f the filter is designed to have a known pass/reject ratio which varies with wavelength, then the wavelength of a narrowband reflection from a single grating can be determined simply by measuring and comparing the passed and rejected intensities. For the filter with a transmission spectrum shown on the left in the figure below, as the Bragg wavelength
3 increases from to, the transmitted intensity t decreases and the reflected or rejected intensity r increases correspondingly. This is the simplest and cheapest way of demodulating FBG, but it has the important disadvantage that it can address only one grating at a time. t reject r transmit λ Figure 2. Demodulating FBG with a passive filter. Wavelength shifts (left) are converted into intensity changes (right). A widely-employed approach is to illuminate the FBG with a narrowband tunable light source. This is the basis of Smart Fibres current products. This method will be dealt with in more detail in the following section, Wavelength Division Multiplexing Wavelength-Division Multiplexing (WDM) The principle behind WDM is simple. Many gratings can be combined on a single fibre and addressed simultaneously provided each has a different Bragg wavelength. This is achieved in practise either by using a broadband light source and a spectrometer for detection or a tunable, swept-wavelength light source and simple photodiode detectors. Smart Fibres employs the latter method in its interrogation units and the diagrams below will help to illustrate how they work. a b d e c g 4 f λ 3 λ 4 h t 1 t 2 t 3 t 4 time λ 3 λ 4
4 Figure 3. Schematic and operating principle of WDM equipment. Key: a) light source, b) scanning filter, c) scan generator, d) coupler network for channels 1-4, e) FBG arrays, f) photodetectors, g) processor and h), timevarying output of the detector on channel 4, showing times t i converted into Bragg wavelengths λ i. The scan generator tunes the light source, sweeping it back and forth across its range such that at any given instant the wavelength of light being transmitted down the fibres is known. When this wavelength coincides with the Bragg wavelength of an FBG, light is reflected back down the fibre to a photodetector. The scan generator also supplies a timing signal to the processor, allowing it to convert the intensity vs. time information into a spectrum. Further processing is performed to identify peaks in this spectrum, find their peak positions and convert these to strain or temperature. Typical characteristics of a WDM system are: High sensitivity and accuracy. State-of-the-art WDM systems routinely achieve 1 pm wavelength resolution and long-term stability of better than 3.5 pm. Therefore, strain sensitivity and accuracy are 0.8 µε and 4 µε respectively. Moderate speed. Scan rates are usually around a hundred Hz. Some sources can scan up to 10 khz but data processing becomes difficult for large numbers of sensors at higher speeds. Flexibility. As long as they have different Bragg wavelengths, any reasonable number of sensors can be placed anywhere on a given fibre. Sensors could be 10 mm or 1 km apart, they are read in the same way. Because the FBG reflections and the light sources both have finite widths (typically < 0.5 nm and 50 nm respectively) a practical limit on the number of sensors that can be accommodated is about 100 per channel. Relatively large size. The swept light is a fairly complex, delicate component. Together with the need for significant on-board processing power, this dictates a unit of comparable size to a desktop PC. Smaller size can of course be achieved, but at a cost. Thus, WDM units have historically been more suited to laboratory use or certain environments, such as may be found in civil engineering or marine applications, where their size has not been a drawback. They are less suited for use in aircraft or wheeled vehicles. Note that devices based on grating spectrometers with array detectors can be small and robust. Time-Division Multiplexing (TDM) A TDM system employs a pulsed broadband light source and identifies different gratings by the time taken for their return signals to reach a detector. The pulses from closer gratings are received before those from more distant FBG. The figure below shows an array of FBG at different distances l from the interrogation unit. The time t i required for a pulse return from an FBG at l i is given by: t = l c i (3) n i 2 where c is the speed of light in vacuo and n is the fibre refractive index. Having established the position of a grating in an array, a system of passive sloped filters, as described previously, is used to determine the wavelength of each pulse as it arrives.
5 l 3 l 2 a b l 1 d e c λ 3 output pulse reflected pulses t 0 t 1 t 2 t 3 time Figure 4. TDM system. Top: Pulses from light source (a) pass through coupler (b), which is also connected to detector (c), to fibre (d) containing FBG (e). Bottom: pulses emanating from source at time t 0 are reflected from FBG at l 1, l 2 and l 3, and return at t 1, t 2 and t 3. Characteristics of a TDM system are: Low cost. There are no sophisticated tunable lasers or filters so the unit can be cheaper than a WDM system Light and rugged. All processing is done with solid state electronics. There are no moving parts so a TDM-based system has the potential to be very small and robust, hence suitable for use in more hostile environments and applications. High sampling rate. Sampling rate is determined only by processing speed and not restricted by the scan rate of the light source. Sample rates of a few khz are readily attainable. Sensor spacing. The main restriction in a TDM system is that the sensors must be sufficiently far apart for pulses returning from adjacent sensors to be separated temporally. 3) Summary FBG can be used as sensitive, stable, strain and temperature sensors or built into transducers for other measurands such as pressure, acceleration etc. Key advantages of FBG over other types of fibre-optic sensor are: minimal size, high strength, linearity, robust signal and ease of multiplexing. Cross-sensitivity to strain and temperature can be a drawback. WDM interrogation methods offer high resolution, accuracy and stability, flexibility in addressing moderate numbers of sensors and relatively low sampling rates. They are well-developed but relatively high cost. Commercial TDM-based systems are less common but they offer faster sampling in a lower cost, more rugged unit than WDM. Sensor spacing is less flexible than is allowed by WDM.
PIPELINE LEAKAGE DETECTION USING FIBER-OPTIC DISTRIBUTED STRAIN AND TEMPERATURE SENSORS WHITE PAPER
PIPELINE LEAKAGE DETECTION USING FIBER-OPTIC DISTRIBUTED STRAIN AND TEMPERATURE SENSORS WHITE PAPER Lufan Zou and Taha Landolsi OZ Optics Limited, 219 Westbrook Road, Ottawa, ON, Canada, K0A 1L0 E-mail:
More informationIntroduction to Add-Drop Multiplexers
3 Introduction to Add-Drop Multiplexers In this chapter different channel routing technologies are reviewed, highlighting the advantages and drawbacks of the different devices and configurations. The parameters
More informationModule 13 : Measurements on Fiber Optic Systems
Module 13 : Measurements on Fiber Optic Systems Lecture : Measurements on Fiber Optic Systems Objectives In this lecture you will learn the following Measurements on Fiber Optic Systems Attenuation (Loss)
More informationInterferometric Measurement of Dispersion in Optical Components
Interferometric Measurement of Dispersion in Optical Components Mark Froggatt, Eric Moore, and Matthew Wolfe Luna Technologies, Incorporated, 293-A Commerce Street, Blacksburg, Virginia 246 froggattm@lunatechnologies.com.
More informationFTIR Instrumentation
FTIR Instrumentation Adopted from the FTIR lab instruction by H.-N. Hsieh, New Jersey Institute of Technology: http://www-ec.njit.edu/~hsieh/ene669/ftir.html 1. IR Instrumentation Two types of instrumentation
More informationImproving Chromatic Dispersion and PMD Measurement Accuracy
Improving Chromatic Dispersion and PMD Measurement Accuracy White Paper Michael Kelly Agilent Technologies Signal transmission over optical fibers relies on preserving the waveform from transmitter to
More informationPUMPED Nd:YAG LASER. Last Revision: August 21, 2007
PUMPED Nd:YAG LASER Last Revision: August 21, 2007 QUESTION TO BE INVESTIGATED: How can an efficient atomic transition laser be constructed and characterized? INTRODUCTION: This lab exercise will allow
More informationAnalysis and Improvement of Mach Zehnder Modulator Linearity Performance for Chirped and Tunable Optical Carriers
886 JOURNAL OF LIGHTWAVE TECHNOLOGY, VOL. 20, NO. 5, MAY 2002 Analysis and Improvement of Mach Zehnder Modulator Linearity Performance for Chirped and Tunable Optical Carriers S. Dubovitsky, Member, IEEE,
More informationDesigning Fiber Optic Systems David Strachan
Designing Fiber Optic Systems David Strachan Everyone knows that fiber optics can carry a huge amount of data. There are more benefits to using fiber optics in broadcast applications than you might realize.
More informationMeasuring Laser Power and Energy Output
Measuring Laser Power and Energy Output Introduction The most fundamental method of checking the performance of a laser is to measure its power or energy output. Laser output directly affects a laser s
More informationHigh Power and Low Coherence Fibre-optic Source for Incoherent Photonic Signal Processing
High Power and Low Coherence Fibre-optic Source for Incoherent Photonic Signal Processing Y u a n L i a n d R o b e r t A. M i n a s i a n School of Electrical and Information Engineering and APCRC University
More informationHow To Read A Fiber Optic Sensor
2572-17 Winter College on Optics: Fundamentals of Photonics - Theory, Devices and Applications 10-21 February 2014 Optical Fiber Sensors Basic Principles Scuola Superiore Sant'Anna Pisa Italy Optical Fiber
More informationFundamentals of modern UV-visible spectroscopy. Presentation Materials
Fundamentals of modern UV-visible spectroscopy Presentation Materials The Electromagnetic Spectrum E = hν ν = c / λ 1 Electronic Transitions in Formaldehyde 2 Electronic Transitions and Spectra of Atoms
More informationDispersion in Optical Fibers
Dispersion in Optical Fibers By Gildas Chauvel Anritsu Corporation TABLE OF CONTENTS Introduction Chromatic Dispersion (CD): Definition and Origin; Limit and Compensation; and Measurement Methods Polarization
More informationE190Q Lecture 5 Autonomous Robot Navigation
E190Q Lecture 5 Autonomous Robot Navigation Instructor: Chris Clark Semester: Spring 2014 1 Figures courtesy of Siegwart & Nourbakhsh Control Structures Planning Based Control Prior Knowledge Operator
More informationA Simple Fiber Optic displacement Sensor for Measurement of Light Intensity with the Displacement
A Simple Fiber Optic displacement Sensor for Measurement of Light Intensity with the Displacement Trilochan patra Assistant professor, Department of Electronics and Communication Engineering, Techno India
More informationFIBER LASER STRAIN SENSOR DEVICE
FIBER LASER STRAIN SENSOR DEVICE E. Maccioni (1,2), N. Beverini (1,2), M. Morganti (1,2) F. Stefani (2,3), R. Falciai (4), C. Trono (4) (1) Dipartimento di Fisica E. Fermi Pisa (2) INFN Sez. Pisa (3) Dipartimento
More informationAcousto-optic modulator
1 of 3 Acousto-optic modulator F An acousto-optic modulator (AOM), also called a Bragg cell, uses the acousto-optic effect to diffract and shift the frequency of light using sound waves (usually at radio-frequency).
More informationExperiment 5. Lasers and laser mode structure
Northeastern University, PHYS5318 Spring 2014, 1 1. Introduction Experiment 5. Lasers and laser mode structure The laser is a very important optical tool that has found widespread use in science and industry,
More informationBOTDR Measurement Techniques and Brillouin Backscatter Characteristics of Corning Single-Mode Optical Fibers
BOTDR Measurement Techniques and Brillouin Backscatter Characteristics of Corning Single-Mode Optical Fibers WP4259 Issued: January 2015 Brillouin Optical Time Domain Reflectometry The Brillouin Optical
More informationPractical Application of Industrial Fiber Optic Sensing Systems
Practical Application of Industrial Fiber Optic Sensing Systems John W. Berthold and David B. Needham Davidson Instruments, Inc. P.O. Box 130100, The Woodlands, TX 77393 ABSTRACT In this presentation,
More informationLine Monitoring and Control in Subsea Networks
Line Monitoring and Control in Subsea Networks This paper discusses how submerged equipment is monitored and contrasts different methods of doing this. It also considers what features are required by the
More informationFIBER BRAGG GRATING SENSORS: NEW IDEAS ON STRAIN- TEMPERATURE DISCRIMINATION
INTERNATIONAL JOURNAL ON SMART SENSING AND INTELLIGENT SYSTEMS VOL. 3, NO. 1, MARCH 2010 FIBER BRAGG GRATING SENSORS: NEW IDEAS ON STRAIN- TEMPERATURE DISCRIMINATION Aashia Rahman and Sundarrajan Asokan
More informationVOLUME BRAGG GRATINGS TM A NEW PLATFORM TECHNOLOGY FOR WDM APPLICATIONS. Boris L. Volodin, Sergei V. Dolgy, Elena D. Melnik and Vladimir S.
VOLUME BRAGG GRATINGS TM A NEW PLATFORM TECHNOLOGY FOR WDM APPLICATIONS Boris L. Volodin, Sergei V. Dolgy, Elena D. Melnik and Vladimir S. Ban, PD-LD Inc. Pennington, NJ 08534 Introduction The development
More informationIntroduction to Fourier Transform Infrared Spectrometry
Introduction to Fourier Transform Infrared Spectrometry What is FT-IR? I N T R O D U C T I O N FT-IR stands for Fourier Transform InfraRed, the preferred method of infrared spectroscopy. In infrared spectroscopy,
More informationA comparison of radio direction-finding technologies. Paul Denisowski, Applications Engineer Rohde & Schwarz
A comparison of radio direction-finding technologies Paul Denisowski, Applications Engineer Rohde & Schwarz Topics General introduction to radiolocation Manual DF techniques Doppler DF Time difference
More information(Refer Slide Time: 2:10)
Data Communications Prof. A. Pal Department of Computer Science & Engineering Indian Institute of Technology, Kharagpur Lecture-12 Multiplexer Applications-1 Hello and welcome to today s lecture on multiplexer
More informationRobot Perception Continued
Robot Perception Continued 1 Visual Perception Visual Odometry Reconstruction Recognition CS 685 11 Range Sensing strategies Active range sensors Ultrasound Laser range sensor Slides adopted from Siegwart
More informationLoad monitoring for wind turbines
Load monitoring for wind turbines Fibre optic sensing and data processing T.W. Verbruggen ECN-E--09-071 Acknowledgement/Preface This report is written in the context of the project Measurement system Load
More informationSol: Optical range from λ 1 to λ 1 +Δλ contains bandwidth
1. Use Figure 3.47 and Figure 3.50 to explain why the bandwidth of twisted-wire pairs and coaxial cable decreases with distance. Figure 3.47 figure 3.50 sol: The bandwidth is the range of frequencies where
More informationA Guide to Acousto-Optic Modulators
A Guide to Acousto-Optic Modulators D. J. McCarron December 7, 2007 1 Introduction Acousto-optic modulators (AOMs) are useful devices which allow the frequency, intensity and direction of a laser beam
More informationMultiplexing. Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single physical medium.
Multiplexing Multiplexing is the set of techniques that allows the simultaneous transmission of multiple signals across a single physical medium. The following two factors in data communications lead to
More informationINTRODUCTION FIGURE 1 1. Cosmic Rays. Gamma Rays. X-Rays. Ultraviolet Violet Blue Green Yellow Orange Red Infrared. Ultraviolet.
INTRODUCTION Fibre optics behave quite different to metal cables. The concept of information transmission is the same though. We need to take a "carrier" signal, identify a signal parameter we can modulate,
More informationSolution 1: Algorithm Positioning
Model No: OEAFP Series All-Fiber Pipeline Security System Solutions Solution 1: Algorithm Positioning Application conditions Applicable for outdoor long-distance oil-gas pipeline security monitoring without
More informationMeasuring of optical output and attenuation
Measuring of optical output and attenuation THEORY Measuring of optical output is the fundamental part of measuring in optoelectronics. The importance of an optical power meter can be compared to an ammeter
More informationAgilent 8509C Lightwave Polarization Analyzer
Agilent 8509C Lightwave Polarization Analyzer Product Overview Highly accurate and repeatable polarization measurements of signal and components 1280 nm to 1640 nm L-Band extended wavelength option High
More informationChallenges in DWDM System Spectral Analysis By Laurent Begin and Jim Nerschook
Challenges in DWDM System Spectral Analysis By Laurent Begin and Jim Nerschook TABLE OF CONTENTS: 1.0 Satisfying the Thirst for Bandwidth 02 2.0 The Solution, DWDM 02 3.0 Resolution 04 4.0 Wavelength Accuracy
More informationRF Network Analyzer Basics
RF Network Analyzer Basics A tutorial, information and overview about the basics of the RF Network Analyzer. What is a Network Analyzer and how to use them, to include the Scalar Network Analyzer (SNA),
More informationWAVELENGTH OF LIGHT - DIFFRACTION GRATING
PURPOSE In this experiment we will use the diffraction grating and the spectrometer to measure wavelengths in the mercury spectrum. THEORY A diffraction grating is essentially a series of parallel equidistant
More informationREMOTE BRIDGE MONITORING SYSTEM WITH OPTICAL FIBER SENSORS
13 th World Conference on Earthquake Engineering Vancouver, B.C., Canada August 1-6, 2004 Paper No. 677 REMOTE BRIDGE MONITORING SYSTEM WITH OPTICAL FIBER SENSORS TZU-KANG LIN 1, YUN-BIN LIN 1, KUO-CHUN
More informationFiber Optic Distributed Temperature Sensor (B-DTS)
Fiber Optic Distributed Temperature Sensor (B-DTS) Low-cost Brillouin BOTDA scattering version For more information about our strain and temperature sensor system and related products, please visit www.ozoptics.com
More informationFIBRE-OPTICS POWER METER INSTRUCTION MANUAL
FIBRE-OPTICS POWER METER INSTRUCTION MANUAL FIBRE-OPTICS POWER METER ELLMAX ELECTRONICS LTD. Unit 29, Leyton Business Centre, Etloe Road, Leyton, London E10 7BT, England Tel: 020-8539 0136 Fax: 020-8539
More informationFIBER OPTIC COMMUNICATIONS. Optical Fibers
FIBER OPTIC COMMUNICATIONS Optical Fibers Fiber optics (optical fibers) are long, thin strands of very pure glass about the size of a human hair. They are arranged in bundles called optical cables and
More informationData Transmission. Data Communications Model. CSE 3461 / 5461: Computer Networking & Internet Technologies. Presentation B
CSE 3461 / 5461: Computer Networking & Internet Technologies Data Transmission Presentation B Kannan Srinivasan 08/30/2012 Data Communications Model Figure 1.2 Studying Assignment: 3.1-3.4, 4.1 Presentation
More informationOptical Communications
Optical Communications Telecommunication Engineering School of Engineering University of Rome La Sapienza Rome, Italy 2005-2006 Lecture #2, May 2 2006 The Optical Communication System BLOCK DIAGRAM OF
More informationDIRECTIONAL FIBER OPTIC POWER MONITORS (TAPS/PHOTODIODES)
Features: DIRECTIONAL FIBER OPTIC POWER MONITORS (TAPS/PHOTODIODES) PATENT NUMBERS: CANADA 2,494,133, USA 7095931, 7295731 AND CHINA 1672073 Telcordia GR-468 qualified Available in versions for any wavelength
More informationSpectroscopy. Biogeochemical Methods OCN 633. Rebecca Briggs
Spectroscopy Biogeochemical Methods OCN 633 Rebecca Briggs Definitions of Spectrometry Defined by the method used to prepare the sample 1. Optical spectrometry Elements are converted to gaseous atoms or
More informationSection 3. Sensor to ADC Design Example
Section 3 Sensor to ADC Design Example 3-1 This section describes the design of a sensor to ADC system. The sensor measures temperature, and the measurement is interfaced into an ADC selected by the systems
More informationEECC694 - Shaaban. Transmission Channel
The Physical Layer: Data Transmission Basics Encode data as energy at the data (information) source and transmit the encoded energy using transmitter hardware: Possible Energy Forms: Electrical, light,
More informationFiber Optics: Fiber Basics
Photonics Technical Note # 21 Fiber Optics Fiber Optics: Fiber Basics Optical fibers are circular dielectric wave-guides that can transport optical energy and information. They have a central core surrounded
More informationFour Wave Mixing in Closely Spaced DWDM Optical Channels
544 VOL. 1, NO. 2, AUGUST 2006 Four Wave Mixing in Closely Spaced DWDM Optical Channels Moncef Tayahi *, Sivakumar Lanka, and Banmali Rawat Advanced Photonics Research lab, Department of Electrical Engineering
More informationDDX 7000 & 8003. Digital Partial Discharge Detectors FEATURES APPLICATIONS
DDX 7000 & 8003 Digital Partial Discharge Detectors The HAEFELY HIPOTRONICS DDX Digital Partial Discharge Detector offers the high accuracy and flexibility of digital technology, plus the real-time display
More informationIntroduction to Optical Link Design
University of Cyprus Πανεπιστήµιο Κύπρου 1 Introduction to Optical Link Design Stavros Iezekiel Department of Electrical and Computer Engineering University of Cyprus HMY 445 Lecture 08 Fall Semester 2014
More informationFiber Optics: Engineering from Global to Nanometer Dimensions
Fiber Optics: Engineering from Global to Nanometer Dimensions Prof. Craig Armiento Fall 2003 1 Optical Fiber Communications What is it? Transmission of information using light over an optical fiber Why
More informationSuppression of Four Wave Mixing in 8 Channel DWDM System Using Hybrid Modulation Technique
International Journal of Electronic and Electrical Engineering. ISSN 0974-2174, Volume 7, Number 2 (2014), pp. 97-108 International Research Publication House http://www.irphouse.com Suppression of Four
More informationA compact, lightweight, portable optical spectrum analyzer for DWDM system installation and maintenance.
A compact, lightweight, portable optical spectrum analyzer for DWDM system installation and maintenance. Bulletin -01E http://www.yokogawa.com/tm/... Visit our website to sign for e-mail updates Compact,
More informationBasic RTD Measurements. Basics of Resistance Temperature Detectors
Basic RTD Measurements Basics of Resistance Temperature Detectors Platinum RTD resistances range from about 10 O for a birdcage configuration to 10k O for a film type, but the most common is 100 O at 0
More informationReal-time In-Flight Strain and Deflection Monitoring with Fiber Optic Sensors
Real-time In-Flight Strain and Deflection Monitoring with Fiber Optic Sensors Dr. Lance Richards, Allen R. Parker, Dr. William L. Ko, Anthony Piazza Dryden Flight Research Center, Edwards, CA Space Sensors
More informationLimiting factors in fiber optic transmissions
Limiting factors in fiber optic transmissions Sergiusz Patela, Dr Sc Room I/48, Th. 13:00-16:20, Fri. 9:20-10:50 sergiusz.patela@pwr.wroc.pl eportal.pwr.wroc.pl Copying and processing permitted for noncommercial
More information# 2. Selecting and Using Thermistors for Temperature Control
# 2 Selecting and Using Thermistors for Temperature Control Selecting and Using Thermistors for Temperature Control Thermally sensitive resistors (thermistors) are used widely in laser diode and detector
More informationSimulation of Gaussian Pulses Propagation Through Single Mode Optical Fiber Using MATLAB . MATLAB
Iraqi Journal of Science, 213, Vol.4, No.3, pp.61-66 Simulation of Gaussian Pulses Propagation Through Single Mode Optical Fiber Using MATLAB Salah Al Deen Adnan Taha *, Mehdi M. Shellal, and Ahmed Chyad
More informationBragg Grating Simulation Software
Bragg Grating Simulation Software Chris Brooks and Claire Davis Air Vehicles Division Defence Science and Technology Organisation DSTO-TN-0800 ABSTRACT (U) This document is a user manual for a software
More informationSynthetic Sensing: Proximity / Distance Sensors
Synthetic Sensing: Proximity / Distance Sensors MediaRobotics Lab, February 2010 Proximity detection is dependent on the object of interest. One size does not fit all For non-contact distance measurement,
More information3.5.4.2 One example: Michelson interferometer
3.5.4.2 One example: Michelson interferometer mirror 1 mirror 2 light source 1 2 3 beam splitter 4 object (n object ) interference pattern we either observe fringes of same thickness (parallel light) or
More informationComponents for Infrared Spectroscopy. Dispersive IR Spectroscopy
Components for Infrared Spectroscopy Mid-IR light: 00-000 cm - (5.5 m wavelength) Sources: Blackbody emitters Globar metal oxides Nernst Glower: Silicon Carbide Detectors: Not enough energy for photoelectric
More informationSensori ottici e laser nelle applicazioni industriali
Sensori ottici e laser nelle applicazioni industriali Guido GIULIANI Pavia giuliani@julight.it 1 Outline Optical sensors in industry: why? Types of optical sensors optical barriers distance measurement
More informationProblem Set 6 UV-Vis Absorption Spectroscopy. 13-1. Express the following absorbances in terms of percent transmittance:
Problem Set 6 UV-Vis Absorption Spectroscopy 13-1. Express the following absorbances in terms of percent transmittance: a 0.051 b 0.918 c 0.379 d 0.261 e 0.485 f 0.072 A = log P o /P = log1/t = - log T
More informationMultipath fading in wireless sensor mote
Multipath fading in wireless sensor mote Vaishali M.Tech (VLSI), IMSEC, Ghaziabad/MTU, Noida Abstract: In this paper we study about the new technology as to transfer the data with the help of smart device,
More informationiva Cable & Antenna Analyzer
iva Cable & Antenna Analyzer VSWR, Return Loss Measurement & Distance to Fault The iva Series Cable & Antenna Analyzer is an exciting new product from Kaelus that enables users to accurately measure VSWR/return
More informationWDM-PON: A VIABLE ALTERNATIVE FOR NEXT GENERATION FTTP
WDM-PON: A VIABLE ALTERNATIVE FOR NEXT GENERATION FTTP AN ENABLENCE ARTICLE WRITTEN BY DR. MATT PEARSON, VP TECHNOLOGY PUBLISHED IN FTTH PRISIM MAGAZINE March, 2010 www.enablence.com Most of the Fiber-to-the-Home
More informationLab 9: The Acousto-Optic Effect
Lab 9: The Acousto-Optic Effect Incoming Laser Beam Travelling Acoustic Wave (longitudinal wave) O A 1st order diffracted laser beam A 1 Introduction qb d O 2qb rarefractions compressions Refer to Appendix
More informationAbout Coffee and Refractometers 2008-2010 Voice Systems Technology, Inc. (VST)
About Coffee and Refractometers 2008-200 Voice Systems Technology, Inc. (VST) www.mojotogo.us.0 Coffee and Refractive Index Refractive Index measurements have been used for process control in the food
More informationOptical Fibres. Introduction. Safety precautions. For your safety. For the safety of the apparatus
Please do not remove this manual from from the lab. It is available at www.cm.ph.bham.ac.uk/y2lab Optics Introduction Optical fibres are widely used for transmitting data at high speeds. In this experiment,
More informationWe bring quality to light. MAS 40 Mini-Array Spectrometer. light measurement
MAS 40 Mini-Array Spectrometer light measurement Features at a glance Cost-effective and robust CCD spectrometer technology Standard USB interface Compatible with all Instrument Systems measuring adapters
More informationImpedance 50 (75 connectors via adapters)
VECTOR NETWORK ANALYZER PLANAR TR1300/1 DATA SHEET Frequency range: 300 khz to 1.3 GHz Measured parameters: S11, S21 Dynamic range of transmission measurement magnitude: 130 db Measurement time per point:
More informationSelecting Receiving Antennas for Radio Tracking
Selecting Receiving Antennas for Radio Tracking Larry B Kuechle, Advanced Telemetry Systems, Inc. Isanti, Minnesota 55040 lkuechle@atstrack.com The receiving antenna is an integral part of any radio location
More informationHigh-speed demodulation of long-gauge fibre optic strain sensors for dynamic structural monitoring
High-speed demodulation of long-gauge fibre optic strain sensors for dynamic structural monitoring Daniele Inaudi, Branko Glisic, Daniele Posenato 1 ABSTRACT Long-gauge interferometric SOFO sensors have
More informationFundamentals of Telecommunications
Fundamentals of Telecommunications Professor of CIS Columbus, OH 43210 Jain@ACM.Org http://www.cis.ohio-state.edu/~jain/ 1 Overview Time Division Multiplexing T1, T3, DS1, E1 T1 Framing Echo Cancellation
More informationNetwork Design. Yiannos Mylonas
Network Design Yiannos Mylonas Physical Topologies There are two parts to the topology definition: the physical topology, which is the actual layout of the wire (media), and the logical topology, which
More informationGLOBAL COLLEGE OF ENGINEERING &TECHNOLOGY: YSR DIST. Unit VII Fiber Optics Engineering Physics
Introduction Fiber optics deals with the light propagation through thin glass fibers. Fiber optics plays an important role in the field of communication to transmit voice, television and digital data signals
More informationHigh-Reliability Diode Lasers for Gesture Recognition. Applying Telecommunications Reliability Design to Consumer Electronics
High-Reliability Diode Lasers for Gesture Recognition Applying Telecommunications Reliability Design to Consumer Electronics www.lumentum.com Application Note A wide range of consumer-electronics applications
More informationElectronic Communications Committee (ECC) within the European Conference of Postal and Telecommunications Administrations (CEPT)
Page 1 Electronic Communications Committee (ECC) within the European Conference of Postal and Telecommunications Administrations (CEPT) ECC RECOMMENDATION (06)01 Bandwidth measurements using FFT techniques
More informationGermanium Diode AM Radio
Germanium Diode AM Radio LAB 3 3.1 Introduction In this laboratory exercise you will build a germanium diode based AM (Medium Wave) radio. Earliest radios used simple diode detector circuits. The diodes
More informationScanning Near Field Optical Microscopy: Principle, Instrumentation and Applications
Scanning Near Field Optical Microscopy: Principle, Instrumentation and Applications Saulius Marcinkevičius Optics, ICT, KTH 1 Outline Optical near field. Principle of scanning near field optical microscope
More informationEXPERIMENT 11 UV/VIS Spectroscopy and Spectrophotometry: Spectrophotometric Analysis of Potassium Permanganate Solutions.
EXPERIMENT 11 UV/VIS Spectroscopy and Spectrophotometry: Spectrophotometric Analysis of Potassium Permanganate Solutions. Outcomes After completing this experiment, the student should be able to: 1. Prepare
More informationExplanation of Reflection Features in Optical Fiber as Sometimes Observed in OTDR Measurement Traces
Explanation of Reflection Features in Optical Fiber as Sometimes Observed in OTDR Measurement Traces WP1281 Issued: November 2015 Supersedes: 2012 Author: Dr. Russell Ellis ISO 9001 Registered Background
More informationFiber Optic Network Marketing - Current Technologies
Advanced Test Equipment Can Shorten TIme To Market For New Fiber Optic Communication Gear Raj Nair Keithley Instruments Inc. The recent battering of optical network and related stocks, along with those
More informationUltrasound Distance Measurement
Final Project Report E3390 Electronic Circuits Design Lab Ultrasound Distance Measurement Yiting Feng Izel Niyage Asif Quyyum Submitted in partial fulfillment of the requirements for the Bachelor of Science
More informationUV-Vis spectrophotometers
UV-Vis spectrophotometers an Advanced Digital Technology EXPERIENCE SECOMAM is proud to provide the new fourthgeneration UVIKON ultraviolet-visible spectrophotometers.with more than five decades of experience
More informationThe Fundamentals of Infrared Spectroscopy. Joe Van Gompel, PhD
TN-100 The Fundamentals of Infrared Spectroscopy The Principles of Infrared Spectroscopy Joe Van Gompel, PhD Spectroscopy is the study of the interaction of electromagnetic radiation with matter. The electromagnetic
More informationHas profound implications for the efficiency with which non-linear light is generated!
Non-Linear Optics Lecture 3: Achieving Phase Matching Learning goals By the end of this lecture you should: Show that we can use refractive index ellipsoids to define particular directions for phase matching.
More informationOptical Metrology. Third Edition. Kjell J. Gasvik Spectra Vision AS, Trondheim, Norway JOHN WILEY & SONS, LTD
2008 AGI-Information Management Consultants May be used for personal purporses only or by libraries associated to dandelon.com network. Optical Metrology Third Edition Kjell J. Gasvik Spectra Vision AS,
More informationModule 5. Broadcast Communication Networks. Version 2 CSE IIT, Kharagpur
Module 5 Broadcast Communication Networks Lesson 1 Network Topology Specific Instructional Objectives At the end of this lesson, the students will be able to: Specify what is meant by network topology
More informationCommunication Systems
AM/FM Receiver Communication Systems We have studied the basic blocks o any communication system Modulator Demodulator Modulation Schemes: Linear Modulation (DSB, AM, SSB, VSB) Angle Modulation (FM, PM)
More informationInterferometers. OBJECTIVES To examine the operation of several kinds of interferometers. d sin = n (1)
Interferometers The true worth of an experimenter consists in his pursuing not only what he seeks in his experiment, but also what he did not seek. Claude Bernard (1813-1878) OBJECTIVES To examine the
More informationA NEW LOOK AT RISLEY PRISMS. By Craig Schwarze Senior Systems Engineer OPTRA Inc.
As seen in Photonics Spectra June 2006: A NEW LOOK AT RISLEY PRISMS By Craig Schwarze Senior Systems Engineer OPTRA Inc. Introduction With laser beams finding more and more applications that require aiming
More informationALMA Memo No. 519 An alternative scheme of round-trip phase correction
ALMA Memo No. 519 An alternative scheme of round-trip phase correction Hitoshi KIUCHIa and Masoto ISHIGUROa anational Astronomical Observatory of Japan, 2-21-1 Osawa, Mitaka, Tokyo 181-8588, Japan, hitoshi.kiuchi@nao.ac.jp,
More informationCWDM: lower cost for more capacity in the short-haul
MARCUS NEBELING, Fiber Network Engineering The opportunity to add two to eight wavelengths per fiber allows network designers to increase capacity without installing costly DWDM systems. Fiber Network
More informationHP 70950B OPTICAL SPECTRUM ANALYZER
HP 71450B, 71451B, and 71452B Optical Spectrum Analyzers Technical Specifications Spectral Measurements from 600 to 1700 nm HP 70950B OPTICAL SPECTRUM ANALYZER OPTICAL INPUT The HP 71450B, 71451B, and
More informationS2000 Spectrometer Data Sheet
Description The Ocean Optics OEM S2000 Spectrometer includes the linear CCD-array optical bench, plus the circuits necessary for spectrometer operation. The result is a compact, flexible system with no
More information