OPTICAL SENSORS AND THEIR APPLICATIONS
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Transcript OPTICAL SENSORS AND THEIR APPLICATIONS
OPTICAL SENSORS AND
THEIR APPLICATIONS
PRESENTED BY
GAURAV PURI
ELECTRICAL ENGINEERING
SUNY AT BUFFALO
[email protected]
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TOPICS INCLUDED IN THIS
PRESENTATION
INTRODUCTION
WHY
OPTICAL SENSORS ?
PRINCIPLE OF OPTICAL SENSORS
CLASSIFICATION AND COMPARISON
SOME INTERESTING APPLICATIONS
WHERE DO WE GO FROM HERE ?
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INTRODUCTION
NEW
REVOLUTION OF OPTICAL
FIBER SENSORS
IT IS A “SPIN-OFF” FROM OTHER
OPTICAL TECHNOLOGIES
SEEING THE POTENTIAL IN
SENSING APPLICATIONS –
DEVELOPED AS ITS OWN FIELD
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WHY OPTICAL SENSORS
ELECTROMAGNETIC
IMMUNITY
ELECTRICAL ISOLATION
COMPACT AND LIGHT
BOTH POINT AND DISTRIBUTED
CONFIGURATION
WIDE DYNAMIC RANGE
AMENABLE TO MULTIPLEXING
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OPTICAL SENSOR MEASURANDS
TEMPERATURE
PRESSURE
CHEMICAL
SPECIES
FORCE
FLOW
RADIATION
LIQUID LEVEL
pH
DISPLACEMENT HUMIDITY
VIBRATION
STRAIN
ROTATION
VELOCITY
MAGNETIC
FIELDS
ELECTRIC
FIELDS
ACCELERATION ACOUSTIC
FIELDS
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WORKING PRINCIPLE
• LIGHT BEAM CHANGES BY THE
PHENOMENA THAT IS BEING MEASURED
• LIGHT MAY CHANGE IN ITS FIVE OPTICAL
PROPERTIES i.e INTENSITY, PHASE,
POLARIZATION,WAVELENGTH AND
SPECTRAL DISTRIBUTION
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SENSING DETAILS
EP(t)cos[ωt+θ(t)]
•
•
•
•
INTENSITY BASED SENSORS – EP (t)
FREQUENCY VARYING SENSORS - ωP(t)
PHASE MODULATING SENSING- θ(t)
POLARIZATION MODULATING FIBER SENSING
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CLASSIFICATION
EXTRINSIC SENSORS
WHERE THE LIGHT LEAVES THE FEED OR
TRANSMITTING FIBER TO BE CHANGED BEFORE
IT CONTINUES TO THE DETECTOR BY MEANS
OF THE RETURN OR RECEIVING FIBER
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CLASSIFICATION (contd.)
INTRINSIC SENSORS
INTRINSIC SENSORS ARE DIFFERENT IN THAT THE
LIGHT BEAM DOES NOT LEAVE THE OPTICAL FIBER
BUT IS CHANGED WHILST STILL CONTAINED WITHIN IT.
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COMPARISON OF THE TWO TYPES
EXTRINSIC
INTRINSIC
APPLICATIONS-
APPLICATIONS-
TEMPERATURE,
PRESSURE,LIQUID
LEVEL AND FLOW.
LESS SENSITIVE
EASILY MULTIPLEXED
INGRESS/ EGRESS
CONNECTION
PROBLEMS
EASIER TO USE
LESS EXPENSIVE
ROTATION,
ACCELERATION, STRAIN,
ACOUSTIC PRESSURE
AND VIBRATION.
MORE SENSITIVE
TOUGHER TO MULTIPLEX
REDUCES CONNECTION
PROBLEMS
MORE ELABORATE
SIGNAL DEMODULATION
MORE EXPENSIVE
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SENSOR TYPES
CHEMICAL SENSORS
REMOTE SPECTROSCOPY
GROUNDWATER AND SOIL CONTAMINATION
MAJOR PLAYERS IN CHEMICAL SENSORS
1) PHARMACIA BIOTECH (SWEDEN)
2) FIBERCHEM
3) THE QUANTUM GROUP
TEMPERATURE SENSORS
LARGEST COMMERCIALLY AVAILABLE SENSORS
RANGE -40 deg C TO 1000 deg C
US-SMALL COMPANIES, JAPAN- HITACHI n
SUMITOMO
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STRAIN SENSORS
FIBER BRAGG GRATINGS (FBG)
TECHNOLOGY
SENSES AS LITTLE AS 9 MICROSTRAIN
NRL and UNITED TECHNOLOGY
RESEARCH
BIOMEDICAL SENSORS
SPECTROSCOPIC BIOMEDICAL SENSORS
CO 2, O 2 and pH CAN BE MEASURED
SIMULTANEOUSLY
FLOW MONITORING BY LASER
DOPPLERIMETRY
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FIBERS – OPTHALMOLOGIC APPLICATION
ELECTRICAL AND MAGNETIC
SENSORS
APPEALING- INHERENT DIELECTRIC
NATURE
LESS SENSITIVE TO ELECTROMAGNETIC
INTERFERENCE
SMALL SIZE AND SAFER
THEY ARE ALMOST ALWAYS HYBRID
ABB CORPORATION RESEARCH CENTER
ROTATION SENSOR
BASED ON THE SAGNAC EFFECT
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TWO TYPES RING LASER GYROSCOPE
(RLG) AND FIBER OPTIC GYROSCOPE
(FOG)
US COMPANIES PURSUING HIGH
PERFORMANCE FOG’s (HONEYWELL,
LITTON, NORTHRUP, ALLIED SIGNAL etc.)
PRESSURE SENSORS
EARLIER BASED ON PIEZORESISTIVE
TECHNIQUE
BASED ON MOVABLE DIAPHRAGM
HIGH PERFORMANCE- (POLARIZATION
BASED SENSORS)
OPERATING PRESSURE RANGES FROM 070,000 torr
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DISPLACEMENT AND POSITION
SENSORS
ONE OF THE FIRST OPTOELECTRONIC
SENSORS TO BE DEVELOPED.
SIMPLE SENSORS RELY ON THE CHANGE
IN RETROREFLECTANCE DUE TO A
PROXIMAL MIRROR SURFACE
ALSO REFERRED AS LIQUID LEVEL
SENSORS
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APPLICATIONS
MILITARY AND LAW ENFORCEMENT
THIS SENSOR ENABLES LOW LIGHT IMAGING AT TV FRAME
RATES AND ABOVE WITHOUT THE LIMITATIONS OF VACUM TUBE
BASED SYSTEMS.
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NIGHT VISION CAMERA (contd.)
COMPRISES OF :
AMPLIFIED CCD SENSOR
ANTI BLOOMING TECHNOLOGY
CRYSTAL POLYMER SHUTTER
ADVANTAGES :
EXCEPTIONAL DAY LIGHT RESOLN.
IMMUNE TO OVER EXPOSURE
VERY HIGH CONTARAST LEVELS
NO HALOING OR SCINTILLATIONS
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BIOMETRICS
YOUR FACE, FINGERS AND EYES IN A WHOLE NEW
LIGHT
• IMAGE CAPTURE
• IMAGE PROCESSING
• FEATURE EXTRACTION
• FEATURE COMPARISON
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PARTIAL DISCHARGE DETECTION
USES OPTICAL FIBER SENSORS
OPTICAL FIBER SENSORS ARE BEING TESTED FOR USE
IN DETECTING PARTIAL DISCHARGES IN ELECTRICAL
TRANSFORMERS. PINPOINTING SUCH DISCHARGES IS
ESSENTIAL TO PREVENTING INSULATION BREAKDOWN
AND CATASTROPHIC FAILURES.
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LETS TAKE A LOOK AT
THE CHRONOLOGY
OF OPTICAL
SENSORS
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PUBLICATION AND PATENT
TRENDS
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GEOGRAPHICAL ORIGIN OF
PUBLICATIONS
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GEOGRAPHICAL ORIGIN OF
OPTICAL SENSOR PATENTS
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CONCLUSIONS
LOOKING AT THE INDUSTRY TRENDS
IN THE PAST 2 DECADES AND THE
EXPONENTIAL CURVE IT SEEMS TO
ME THAT THERE IS GOING TO BE A
LOT OF RESEARCH AND
IMPROVEMENTS TO THE EXISTING
SENSORS
OPTICAL SENSORS ARE HERE TO
STAY !!!!
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QUESTIONS ??
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REFERENCES
Optical Sensor Technologies
www.wtec.org/loyola/opto/c6_s3.html
Measuring with LIGHT
www.sensorsmag.com/articles/0500/26main.html
Optical Fiber Sensors
www.ul.ie/elements/Issue6/Optical%20Fibre%20Sensors.
html
Partial Discharge Detection
http://www.photonics.com/spectra/applications/XQ/ASP/ao
aid.328/placement.HomeIndex/QX/read.html
Military and Law Enforcement
http://www.militaryandlaw.com.au/products/l3vision.php
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Pockels Effect
www.scienceworld.wolfram.com/physics/Po
ckelsEffect.html
Distinctive advantages give optical
sensors the edge over conventional
systems
www.eurekalert.org/pub_releases/ 200308/ti-dag081303.php
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THANK YOU FOR YOUR
PATIENCE AND TIME
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