Optická vlákna a vláknovésenzory

Ústav fotoniky a elektroniky, AVČR, v.v.i.

www.ufe.cz/dpt240, www.ufe.cz/~kasik

Ústav fotoniky a elektroniky AV ČR, v.v.i.

- součást Akademie věd ČR = základní výzkum, neuniverzitní- středně velký ústav (cca 100 zaměstnanců)

VÝZKUM:- fotonika (optické senzory, vlnovodná fotonika, optická vlákna)- měření (správa etalonu) přesného času, syntéza řeči

FJFI, OFST 2012

Outline

Fiber-optic sensors* general consideration* materials, structures, coatings* processing and accessories* examples

Summary

LABO * local pH detection* gas sensing (angular distribution meas.) * fluorimeter Jobin-Yvon* decladding, cleaving, splicing

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Fiber-optic SENSORS

Change of output optical signal due to (bio)chemical changes in fiber vicinity.

Source Detector

Continual reversible monitoring of (bio)chemical species and their concentration

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Environmental monitoring, medicine, biology, homeland security ... SENSORS

+ Remote sensing+ Distributed or micro+ Explosive, high-voltage areas, human body

Solution : fiber-optic sensors

Multipoint (distributed) detection

Point detection

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Optical SENSOR consideration

� Method : optical (fluorescence...)

� Optics & chemistry� 1. Planar / fiber-optic� 2. Transducer & imobilization� 3. Spectral range� 4. Structure OF � 5. Implementation

� Feasibility ?? *� Expected utilization

(market)� Price

Requirements:� sensitivity - LOD� selectivity� reproducibility� dynamics - time response� reliability-stability ...

* Parkinson : The more complicated system, the higher probability of its failure.** Murphy : What can go wrong, it will.

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Optical HW consideration

� STRUCTURE : MM (multimode)+ larger core & higher NA => cheap components+ robustness => easy handling, processing

� METHOD (absorption, fluorescence, refractometry...)and chemistry =>

� SPECTRAL RANGE : UV<< VIS+NIR >> IR

+ compatibility with conventional fiber optics+ availability of HW of acceptable price+ low optical losses

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Optical HW requirements

� Durability to the analyte� (glasses > polymers > crystals)

� High transparency in a wide spectral range� (VIS-NIR > UV and IR)

� Suitable refractive index� Common availability of optical hw

� (conventional > special; VIS-NIR > UV & IR)

⇒ Material & structure & coating

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Optical fibers – MATERIALS - UV

200 400 600 800 1000 12001

10

100

1000

Optran UV (CeramOptec GmbH) Suprasil 300 (IPE)

Atte

nuat

ion

[dB

/km

]

Wavelength [nm]

� silica fibers - SUPRASIL n200 nm = 1.55 [ceramoptec.de, OceanO, IPE …]� planar silica, crystalline CaF2 (MgF2) – [edmundoptics, technicalglass …]

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Optical fibers – MATERIALS – VIS/NIR

600 800 1000 1200 1400 1600

1

10

100

1000 PCS GI-telecomm SM-telecomm Polystyrene

OH-

10-10

0,01

0,1

0,316

0,794 Tra

nsm

itted

opt

ical

pow

er

Atte

nuat

ion

[dB

/km

]

Wavelength [nm]

Silica n633 =1.457 & doped silica n633 = 1.45-1.50 [corning, lucent, ocean_o, IPE]Glass (silicate - Simax, Vycor, Pyrex) n588 =1.5-1.95 [schott, LiFaTec.de, IPE…]Plastic n588 =1.5-1.6 [mitsubishi.com, luceat.it, unlimited-inc.com…]

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Optical fibers – MATERIALS - IR

� fluoride glasses [irphotonics.com, univ-rennes1.fr …] (up to ~4 µm) � sapphire [CRYTUR, photran.com, fiberoptictechnology.net …] (up to ~4 µm) � silver-halides AgClxBr1-x (up to 15 µm)� chalco glasses (Se, As2S3, As2Se3…) [oxford-electronics, orc.soton.ac.uk] (< 20 µm) � refractive indexes 2-20um ~ 2 – 2.5 >> silicate glasses

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Optical fibers - STREUCTURES

Conventional

Single-modeØcore 2-15 µmNA 0.1-0.25

Multimode Øcore50-1000 µmNA 0.2-0.5

SM 250/125/7 µm MM 250/200 µmFJFI, OFST 2012

Fiber STRUCTURES for fiber sensors

S-fibers capillaries PCF

SM with LPGFJFI, OFST 2012

Optical fiber COATINGS

� Conventional on-line coating

� Mechanical protection� thickness 4 µm (hard)–100 µm (soft)

� Polysiloxane (nD = 1,41), soft� UV-acrylate (nD = 1,65), hard� Fluorinated UV-acrylate (nD=1,35-1.44), hard� PI – polyimide (nD>1,46), hard� PTFE – teflon (nD = 1,29)

� [Sylgard, DeSolite, Luvantix, DSM Desoto]

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Optical fiber special COATINGS

Special additional coating sol-gel and/or polymers

� Immobilizing of transducers� Tailoring of access of analyte

to the detection site => (porosity, thickness, phobicity)� thickness ~102 nm (!) – several µm

� Dip coating� (planar : spin coating)

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OPTICAL FIBER PROCESSING & ACCESSORIES

� mechanically – stripping tool (pliers) :

� chemically - leaching� trichloethylene (acrylates)� HF acid (siloxanes) � exposition – seconds-

minute

Optical fiber decladding

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Optical fiber cleaving

� primitively : scissors, knife, razor blade (suitable for POF)

� more primitively: fire

� correctly : � fiber cleaver FK11

(York Tech, Ericsson)

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Optical fiber splicing

Splicing device (Fujikura, Ericsson), losses ~0.1-0.2 dB

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Optical fiber connectoring

� Types : FC, SMA, APC …; losses ~0.2 dB

125 mglass fiber

µ

Glass gap

Fiber Connection (FC)8 degree angle

Angled Fiber Connection (APC)

Ferrule 2.5 mm Fiber 125 mµ

Alignment key

Connecting body andmechanical retainer

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Optical fiber connectoring

Types : SMA, FC, APC (Angled Physical Contact)

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Optical fibre bundles

Collecting Fiber RingExciting Fiber

� Reflection sensing arrangement (fluorescence)� Imaging� Multianalyte analysis

40 x 120 fibers 125 µm

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Optical fiber tapers

� Multipoint monitoring

Optical losses : SM ~ 0.1-0.2 dB

Tapered fibre: 125 mµ

Fibre waist : 1-10 m2µ

Analyte

Excitation Detection(Transducer)

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Optical fiber tapers

� Small area monitoring� Preparation

� Flame (laser) processing� Slow withdrawing from HF-containing solution

Analyte (cell)

Excitation (2)Excitation (1)Detection

Transducer

Tapered fibre: 125 mµ Τ 1−10 µip: m

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Optical fiber gratings

LPG : Long Period Gratings (~ mm period)

Analyte

(Transducer)

Core mode Cladding mode

LPG period

Preparation� Laser inscription

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Fiber gratings

FBG : Fibre Bragg Gratings (~ nm period)

FBG

LPG : transmission spectrum

1480 1500 1520 1540 1560 1580-64

-60

-56

23.9 26.7 30.7 34.5 38.5 43.2

Out

put s

pect

ral d

ensi

ty (

dBm

/nm

)

Wavelength (nm)

Temperature (°C)

LPG : Long Period Gratings

FBG : reflection spectrum

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EXAMPLESRefractometric sensor of hydrocarbons

+ sensitivity : LOD ~ 3-5 mg/l ~ comparable to EU ecological limit

+ time response : seconds In collaboration with Jean Monnet Saint-Etienne, Ecole Centrale de Lyon

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EXAMPLESLocal pH detection in microsamples

Detection of pH <5; 7> in xylem exudates, intracellular detection

Fiber tapers :

In collaboration with IEB ASCR, UK, MU, VSCHT, MZLU

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Local pH detection in microsamples

� Fluorescence ratiomeric

� HPTS + int.standard Ru-phen

� Laser diode

� taper Ø 8 µm(GI 125/50)

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Liblice

Methods based on fluorescence

475 500 525 550 575 600 625 6500

200

400

600

800

1000 pH6 470nm pH6,25 470nm pH6,5 470nm pH6.75 470nm pH7 470nm pH7,25 470nm pH7,5 470nm pH7,75 470nm pH8 470nm

Out

put p

ower

(a.

u.)

Wavelength (nm)

Intenzity measurement+ easy- incorrect (influence of set-up)* 1 source + detector

Ratiometric

Self-reference1 transducer2 sources +

detector

Internal standard2 transducers1 source

+spectrometer

+ better precision- more complicated set-up

500 550 600 650 700 750 8000,00

0,01

0,02

0,03

0,04

0,05

0,06

I=0.10 mol,l-1Excitation wavelength: 470nm

Response of sensing layer to pH changesc-HPTS complex, standard Ru

Wavelength (nm)

pH 4.05 5.05 6.05 7.1 8.15

Out

put p

ower

(A

.U.)

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Local pH detection in microsamplesFluorescence responses to calibration buffers

Excitation : 475 nm, taper, 8 um, HPTS+Ru-phen

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Local pH detection in microsamples

pH <6; 9> resolution 0.2; pH <5; 6> resolution 0.5 (pH meter ±0,08)

Calibration curve : output = 2,407 – 1,142 pH + 0,133 pH2

buffers

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Local pH detection in microsamples

Time response (10 s)

exudateOpticaly conventionaly

5.6 5.35.5 5.0

within experimental error

Validation

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Implementation for pH detection of drops (6 µl) of xylem exudate of oat

6 lµpH

dropsvolume

5.0 5.4

5.6 5.4

5.5 6.0

Local pH detection in microsamples

No gradient of xylem flow proved.

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SUMMARYSUMMARY

1. Fiber technology : preparation of structures of high preciseness from materials of ultra-high purity (impurities in ppbs only). Two steps : preformpreparation and fiber drawing.

2. Despite of long history of optical fiber sensing, the field is still under development (hot topics – news ~each 3-4 years)

3. Challenges : intracelular & (bio)detection, hydrogen (fuel), distributed environmental monitoring … ?

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I TY se staň UFEm !

UPLATNĚNÍ V OBORU

Příjmy absolventů VŠ po 5 letech praxe

MFD 22/9/20110 10 20 30 40 50

Janáčkova akademie múzických umění v Brně

Mendelova zemědělská a lesnická univerzita v Brně

Akademie múzických umění v Praze

Univerzita Palackého v Olomouci

Veterinární a farmaceutická univerzita Brno

Univerzita Jana Evangelisty Purkyně v Ústí n. Labem

Masarykova univerzita

Technická univerzita v Liberci

Vysoká škola báňská - Technická univ. Ostrava

Univerzita Karlova v Praze

Vysoké učení technické v Brně

Česká zemědělská univerzita v Praze

Vysoká škola chemicko-technologická v Praze

České vysoké učení technické v Praze

Vysoká.škola podnikání, a. s., Ostrava

Vysoká škola ekonomická v Praze

Plat (tis. Kč/měs.)

FJFI, OFST 2012

References� A. Mendez, F.T. Morse : Specialty optical fibers handbook, Elsevier

Science & Technol, USA, 2006. � J. M. Senior : Optical fiber communications - Principle and practise,

Pearson Education Limited, Harlow, England, 2009.� J. Schrofel, K. Novotný : Optické vlnovody, SNTL, 1986 � Saaleh, Fotonika (1 - 4), Matfyzpres� V. Matejec, I. Kasik, M. Chomat : Fundamentals and performance of

the MCVD aerosol process, in Aerosol chemical processes in the environment, Levis (2000)

� K.T.V.Grattan, B.T.Meggitt: : Optical fiber sensor technology, Vol.4, Kluwer, 1999

� G.Boisdé, A.Harmer : Chemical and biochemical sensing with optical fibers and waveguides, Artech House, London, 1996

� J.Dakin, B.Culshaw : Optical fiber sensors, MA, Artech House 97� F.Baldini, A.N.Chester, J.Homola, S.Martelluci, Optical chemical

sensors, Kluwer 2006� O.S. Wolfbeis : Optical sensors, Springer, 2005