FORC Research Updates 2016

FORC Research Retreat, Morib

11 – 13 November, 2016

R E S E A R C H C E N T E R

FORC focuses on design, fabrication and characterization of specialty optical fiberand its application • Rare-earth doped fibers• Microfiber• FBG sensors• LPG sensors• SPR sensors• Polymer PCF• Optical Sensor Network

• Standard MCVD

• Solution Doping, Chelate Delivery

• Pulling Tower

• OSA

• Beam Profiler, Preform Profiler

Fabrication and Characterization Facilities

About us

R E S E A R C H C E N T E R

Simulation and Modelling

People

2 Professors, 1 Associate Professor,

2 Senior Lecturers, 3 Post-docs, 7 PhD,

9 M.Eng.Sc.

Sensors WaveguidesActive

DevicesPassive Devices

O P T I C A L F I B E R FA B R I C AT I O N T E C H N O L O G Y

MCVD Pulling Tower FBG writing Fiber Taper

M AT E R I A L S C I E N C E S

Sensors

• FBG & LPG

• Flat Fiber

• Tapered Fiber

• Doped Dosimeter

• PCF Dosimeter

Waveguides

• Mid infra-red

• Modified Silica Host

• Polymer MOF

Active Devices

• S-band Amplifier

• New Band Amplifier

• Visible Wavelength Fiber Lasers

Passive Devices

• Optical Filter

• Tapered Fiber

• Wavelength converters

• Optical CDMA encoder

Sensors WaveguidesActive

DevicesPassive Devices

O P T I C A L F I B E R FA B R I C AT I O N T E C H N O L O G Y

Optical Sensor Networks

Fiber-to-the-Home

Radiation Dosimetry

Optical Communication Systems

OPTICAL FIBER APPLICATIONS

2014 2015 2016 2017 2018

PROJECT T IMELINES

S-BAND AMPLIFIER

NEW-BAND AMPLIFIER NEW-BAND FIBER NEW-BAND FIBER DEVICES

MICRO-FIBER

FBG OPTICAL CDMA (FRGS)

MICRO-FIBER DEVICES

LPG SENSOR NETWORK (ERGS)

NANOPARTICLE FIBER (FRGS)

BISMUTH FIBER (FRGS)

DOSIMETRY (UM-HIR)

DOSIMETRY OSL & RL (PRGS)

DOSIMETRY TL (FRGS) DOSIMETRY OSL & RL (CRADLE)

POLYMER MOF

DAS SPECIALTY FIBER DAS SYSTEM

OFDMA PON

New Optical Communication Band

Amplifier

• S-band amplifier

• New band amplifier

@ 1700 nm

• Silica host doped

with

• Erbium

• Thulium

• Bismuth

• Glass modifier

• Aluminium

• Gallium

• Barrium

Transmission Fiber

• Silica host

• Photonic Crystal Fiber

• Modified Silica host

Collaborative Project

7

Waveguide Imperfection

Att

enu

atio

n (d

B

km-1

)

0.01

0.050.1

10.5

1050

100

5

0.8 1.0 1.2 1.4 1.6 1.8 2.2 2.4

Wavelength (µm)1

stW

ind

ow

(ea

rly

80

`s)

2n

dW

ind

ow

(m

id 8

0`s

)

C a

nd

L W

ind

ow

(1

99

6)

S-B

and

Win

do

wExperimental Infra-red Absorption

Poss

ible

New

Win

do

w

In-Situ Solution Doping

in-situ solution doping. Bi(NO3)3.5H2O solution is delivered to the tube after soot deposition followed by oxidation, sintering and collapse to a preform.

New BandP23 – Solution doping, Modifier: AlP90 – Solution doping (salt), Modifier: Al

0

5

10

15

20

25

30

35

0 1 2 3 4 5 6 7

Am

plit

ud

e (

dB

m)

Length (m)

Gain P90_125um Gain P23 NF P90_125um NF P23

Comparison of Gain and NF of two Tm doped fiber with different solution doping agents.

Bismuth-doped Fiber• The ranges 1150 – 1500 and 1650 – 1750 nm of the spectral

window 1100 – 1800 nm are not covered by rare-earth fiber lasers and amplifiers.

• Bismuth-doped optical fibers feature a broad luminescence spectrum.

• The optical and lasing properties of Bi-doped fibers are greatly influenced by fiber core composition, Bi concentration, and fabrication technique.

• Optical fiber amplifier for GPON extender with simultaneous operating wavelengths 1310 nm and 1490 nm.

• P2O5 doping of the fiber core leads to the appearance of a band peaking in the region 1300 – 1350 nm.

• Bi concentration is < 200 ppm to avoid clustering.

• Fabrication with MCVD-in situ solution doping.

Bismuth-doped Fiber

Main emission peaks for different Bi-doped fibers

0

5

10

15

20

25

30

35

600 700 800 900 1000 1100 1200 1300 1400 1500 1600 1700

Ab

sorp

tio

n (

dB

)

Wavelength (nm)

NTT Bi7 Bi8

Absorption of Bismuth doped fiber

-70

-60

-50

-40

-30

-20

1250 1300 1350 1400 1450 1500 1550

Am

plit

ud

e (

dB

m)

Wavelength (nm)

Emission of Bismuth doped fiber

808 nm pump with 105 mW power

Dosimetry is a key monitoring technique forsafe and acceptable use of radiation indifferent fields such as

Optical Fiber Radiation Dosimeter

Personal monitoringCalibration high energy machinesMeasuring the dose in small inaccessibleplaces in the body etc.

Fig: Dose measurement using TLD in radiotherapy

Note: The OSL process is similar to the TL process except that the trapped electrons are released optically and not thermally.

Fig : Schematic outline of OSL fiber dosimetry system.

Thermoluminescence Dosimeter (TLD)

Optically Stimulated Luminescence Dosimeter (OSL)

Fig : Schematic outline of TL fiber dosimetry system.

RL Dosimetry System

Fig: Optical fiber-coupled OSL readout system

using Al2O3:C as a sensor

Main components of

RL/OSL dosimeter reader

are:

Sensor Crystal

Optical Detection

System, and

Signal Processing

Electronics

THEORYRadioluminescence

1. Electron-hole pairs generated upon ionizing radiation 2. Radioluminescence is generated due to radiative recombination of the

electron/hole pairs at recombination centers

LINAC, Varian 2100CDGrooves are drilled in some of the solid water slabs to housethe dosimeter probes.

Example of measurement setup Data aquisition

RADIOLUMINESCENCEMETHODS : IRRADIATION

Cylindrical Fiber

Results (RL):

Fig: RL as seen on data acquisition software (Co-60 source)

Cylindrical Fiber

Results (RL):

Fig: Linearity of RL graph for SiO2:Ge at different dose rates

Fig: RL graph for SiO2:Ge at different dose rates

0

5000

10000

15000

20000

0 100 200 300 400 500 600 700 800

Fig: RL response at different absorbed dose

Cylindrical Fiber

Results (RL):

Time (s)

Ph

oto

n c

ou

nts

Fig: Linearity of Total counts vs Absorbed Dose

Cylindrical Fiber

Results (RL):